Being My Sister's Sperm Donor

This is the second part of the Sperm Donar series. It's recommended to read part 1. To review, Sarah and Amy are a lesbian couple. They want children but Sarah is infertile. She wants her wife Amy to have their baby. She also wants her brother Adam, to be the sperm donor. We pick up the story the morning after the first attempt.

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Awkward doesn't describe how I feel this morning. Mortified or terrified beyond belief, might be a better fit. I didn't dare go home. I wandered the streets, trying to think everything through. I was sure what just happened wasn't part of Sarah's master plan.

Firstly, I hadn't expected Amy to do more than just lay there. Her giving me a blow job, whilst amazing, felt like it broke the rules. It wasn't kissing but more intimate than just the mechanical act of sex.

Secondly, I didn't intend for either of them to find out about my fantasy. Especially those about Sarah.

It was true, that Amy had initiated oral sex, and she had seemed to like my fantasies about Sarah. I didn't know what to do, or where to go. At around six I headed home hoping the girls would be asleep. It was silent when I entered the house. I sneaked upstairs to my bedroom, hoping the girls wouldn't hear me.

Crawling into my bed I noticed my pillow smelt of Sarah's perfume. As I drifted off to sleep I breathed in her scent. My dreams strayed into vague sexual fantasies, involving all three of us. Whatever my conscious mind thought, my subconscious seemed to still enjoy the idea.

I slept in late. At midday, I rolled out of bed and headed to the kitchen to make some lunch. In my sleepy stupor, I temporarily forgot why I was feeling so anxious. It came rushing back as I entered the living room and saw Amy and Sarah on the sofa, watching TV. When she saw me Sarah turned it off.

"No Adam, don't leave, can we talk?" She asked earnestly, as I attempted to leave quietly.

"Sit down, we all live here and we're not going anywhere. We need to sort this out," said Amy reassuringly.

Reluctantly I sat down on the sofa opposite them. They both wore small pyjama shorts and hoodies. I couldn't look either of them in the eye.

"Look, Adam, we have been in this situation before," Sarah said empathetically.

"That was different," I said quietly.

"Why because it was us fantasising about you?" Sarah interrupted.

"You've fantasised about me?" I asked my sister confused.

As I recalled it, their fantasy was me fucking Amy, nothing to do with Sarah.

"What Sarah is trying to say," Amy cut in, as Sarah had started to blush a little.

"Is that we all have taboo fantasies from time to time. There is nothing wrong with it. In fact, it's natural. We're happy with how last night went, aren't you?" She said concernedly. I couldn't speak so just nodded.

"Good," said Sarah. "Because if you're up for it, would you be able to perform again tonight?" She asked casually, like asking if I wanted a pizza with them. I looked up surprised.

"It's just that the next week is when Amy is most fertile, it makes sense to try then," Sarah explained.

"Can I talk to Amy about a few things first, on our own?" I asked glancing nervously at Sarah.

"Of course," Sarah said a little taken aback. "How about I pop to the shops to get something for tea," Sarah said hurriedly kissing Amy and then leaving the room.

We sat in silence for a while, Amy seemed to be waiting for me to speak first, but my mind had gone blank. There were loads of things I wanted to talk about, but I didn't know where to start. After what felt like an eternity Amy caved in and spoke.

"So, was there anything specific you wanted to talk about?" Amy said cordially.

"Er, yer. Last night didn't go the way I thought it would," I said slowly.

"Ok, but as I said earlier we all want...." She started to say but this time I cut in.

"No not that, what we did. I expected it to be more clinical, less passionate. I thought It would be, you know, just me in you," I explained.

"Oh, well Sarah said we should try and enjoy it. At least a bit. It helps the fertilisation," Amy replied simply.

"Yer I get that. But It was you giving me a blow job. I just didn't expect it. Does Sarah know about that," I asked timidly

"She knows everything that went on, we have no secrets. It was her suggestion. She suggested I see if my skills were still up to scratch after so long," she answered mischievously. Before marrying my sister Amy had a string of boyfriends.

She laughed at my shocked face and added, "that last part was a joke, she didn't suggest it. All she said was anything was game for us to be comfortable, except kissing. It had been a while and I wanted to re-live some glory days. A rubber cock isn't the same when it comes to blow jobs," she joked.

We settled into an uncomfortable silence. I wanted to know more about Sarah's fantasies. If she had thought of me and her but I was scared to ask. She seemed to read my mind and suggested it would be good for me to have a chat with my sister before tonight. Sort any other concerns.

"I don't know if I can talk to her about this stuff, it's too weird," I said honestly.

"Well, why don't you text her? I texted my dad when I came out as bi, it helped start the conversation off," Amy suggested reasonably.

I nodded and stood up to leave when Amy surprised me by suggesting we watch a film together. Usually, if Sarah wasn't around we gave each other space. Usually, I would be in my room. We didn't hang out together.

She put on an action film. It was nice, the two of us chatted and socialised. We found we liked some of the same music, same films and authors.

Sarah got back a few hours later. Amy offered to run her a bath and put the shopping away for her. Sarah went upstairs for her Bath, Amy suggested texting her now, she always looked at her phone in the bath.

I didn't know how to start. I asked if we could talk. She said we could talk about anything. I took a risk and asked the one question I wanted answered.

Had she ever had a sexual fantasy about me?

She took a long while to respond. My heartbeat increased with the ticking seconds. Her response was blunt, yes. I asked if she would describe it to me, she said no.

We messaged back and forth for the next half hour. She made me realise that my fantasies were ok. They were private, hidden and didn't hurt anyone. She asked if I was still ok for that night, I was.

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Over the next three months, we fell into a strange routine. Amy and I would have sex every night during the week she was most fertile. Then there was a long waiting game until the next window.

Amy and I got more friendly outside the bedroom. We hung out more when Sarah worked long hours, which as a nurse, was quite often. We watched films together, went for walks and even ate out on occasion. Sarah seemed ok with it, and it helped us be more comfortable in bed together. We were more physical with each other too, hugging when we met etc, like how I was with Sarah. Our sex sessions started to follow a similar pattern.

We continued to use Sarah in our role play, fantasy. Amy in particular enjoyed imitating her during the sessions.

After a while, it became less interesting to me. I still fantasied about Sarah, especially during the long periods between fertility weeks. The nights when Sarah and Amy were most vocal I imagined being in the room and joining them. As we got close to the next fertile week I was starting to look forward to being in the moment with Amy more.

On the first night of the next fertile week, we ate a meal together and watched a bit of TV. It didn't feel awkward anymore, we had gone through this enough for it to feel almost natural. It felt like we were all singing from the same hymn sheet, it was liberating.

I started to get excited about tonight's session. Spending so much time with Amy made me feel comfortable.

So far we had strictly kept to the rules. Recently I began to think about those boundaries and was eager to maybe try and move them.

When it got to ten o'clock I said I was going to turn in. I kissed Sarah on the head and waved goodnight to Amy. It was a silly charade we had fallen into. It seemed more natural than Sarah organising us regimentally.

A short while later there was a knock on my door. In walked Amy in a silk dressing gown like she always. Sarah wasn't with her, she hadn't been since the first night. She would wait for Amy in their bedroom. I had already got undressed, laying under the covers. I had a strange feeling of excitement tonight much like the first time. For some reason, I thought tonight would be different. Amy closed the door and turned the light off, like usual, plunging the room into darkness.

I heard her dressing gown fall to the floor and felt the bed move as she sat down. Amy started, sliding her hand up the covers feeling for my legs. She was searching for the outline of my cock. I wasn't hard yet so I reached for her hand and pulled her up to lay beside me. We lay there in the silent darkness for a while.

"What's wrong, doesn't he want to play?" whispered Amy in the darkness.

"Would it be ok if I warmed you up a bit for a change?" I said hopefully.

She had initiated oral sex that first night, and a few others. I had yet to do anything solely for her pleasure. She had needed Sarah to give her an orgasm after each session.

Tonight I wanted to change that. The thought of making her wet, begging me to fuck her, started to make me harden.

Amy thought for a second then shrugged. "You know the rules, no kissing that's it," she said mischievously.

"Sarah also said we should try and enjoy ourselves that first night remember?" I said.

"Oh yes I remember, as long as there's no kissing I don't see the harm," Amy said quietly.

I started to pull the covers down and rolled onto my side. Amy was laying on her side, facing me. Our eyes were getting used to the dark. I could see the outline of her body, her sexy feminine curves and the outline of her face. Her elbow pushed into a pillow as she held her head in her hand.

My hand reached out and started lightly stroking her body. I started at her shoulder, slipping it down her side to her thigh and back up to her hip. Our faces were inches apart, I could make out her perfect features. I wanted to kiss her so badly. I kept stroking her body feeling the goose pimples rise on her skin.

Brushing the flat of my hand over her body, I caressed and massaged her skin. I firmly grasped her bum and squeezed. My cock was stirring as I felt her soft plump bum. I heard a small sigh escape Amy's mouth, warm breath touching my face.

My hand moved back to her shoulder and I gently pushed her onto her back. I continued stroking her body. Tracing along her collar bone and sliding my fingers over her breasts. Amy was responding to my touch, her breathing was getting more pronounced. I needed to taste her but didn't want to overstep the mark, yet.

Lightly I brush my hands over her tits, circling my fingertips around her nipples. I moved down the bed as my hand slid down her body. I looked into Amy's eyes but she had closed them. Would kissing her breasts break the rules?

I took a chance and leant in to kiss the side of her breast. It felt warm under my lips, Amy sighed contently. I took that as a sign of consent and planted little kisses all over her chest. I slipped a nipple into my mouth and sucked. It was hard. I flicked my tongue over it, wetting it with my saliva.

Amy's eyes stayed shut, small moans and groans emanating from those full lips. I kept my attention focused on her chest. Licking her nipples and groping her tits. I climbed on top of her feeling her body warming.

Keeping my hands massaging her breasts, I slowly slid down her body planting kisses on her skin. Amy didn't stop me, emboldened I decided to let her decide how much fun was too much. I reached her toned stomach and stuck my tongue into her belly button. she let out a little giggle. Her body was starting to move, writhing at my touch.

I kept sliding down until my face hovered above her pussy. I tell she was starting to get wet. Sliding my hands to follow my kiss trail, I gently blew on her thighs. My hand reached for her pussy and tentatively I began probing.

"Adam, I'm not sure this is what Sarah had in mind," Amy whispered into the darkness. She had kept her hands by her sides until now. Slowly she raised them to take over rubbing and playing with her nipples.

"Do want me to stop?" I asked as I slipped my fingers through her wet folds. Feeling her swollen clit I started to rub it gently.

"No, don't stop," Amy said breathlessly.

"You like my fingers?" I asked boldly

"Uh-huh," Amy replied quietly.

II slipped a finger inside her, continuing to stimulate her clit with my other hand. Gently I slid my finger in a few centimetres and out again. She felt so warm and wet. I slipped my finger out and sucked the tip, she tasted coppery like a penny. I wanted to taste her, Amy had sucked my cock, this wasn't any different, was it?

I stuck out my tongue and gave her pussy a little lick. Amy moaned as I kept fingering and licking her pussy. She was writhing, legs rubbing the side of my head. Her breath was deepening.

"That feels nice, kept doing that, right there," Amy moaned.

My cock was pushing hard into the mattress, but I wanted Amy to beg for it before I fucked her.

For what felt like an age I kept licking and fingering her pussy. Warm sticky juices coated my mouth. The taste of copper danced on my tongue. Amy was moaning loudly now, her sexy toned body writhed and wriggled. Then she said it.

"Fuck me, Adam I can't take it anymore," she shouted desperately.

I quickly moved up and thrust my cock deep inside her. She let out a little whimper as I started pounding into her pussy. She lifted her legs and clamped them around my waist. The bed was squeaking as I thrust harder and harder. I felt my orgasm building but I didn't want to go so soon. The whole reason for doing this left my mind. I just wanted to keep fucking Amy all night.

I pulled out sharply and tried to flip her over onto all fours.

"What are you doing," Amy said breathlessly, a little confused.

"Turn over," I said firmly.

She quickly turned over presenting her bum in the air. I held my cock, slick with her juices and started teasing her pussy. I rubbed it up her entrance and down again refusing to enter. Amy started moaning again. Resting her head on a pillow she slipped a hand to her pussy, rubbing her clit as I teased her entrance with my cock.

"Don't tease me, Adam I'm so close," Amy shouted out.

I plunged deep inside her, firmly grasped her by the hips and pounded her pussy hard and fast.

"Oh fuck, yer like that baby fuck me," Amy screamed between hard thrusts.

I had only ever heard her call Sarah 'baby'. I kept thrusting harder and faster. Slamming my cock to the hilt, there were slapping sounds as her bum smacked into me. My breathing was getting ragged. I just kept going faster and faster for as long as I could.

"Jesus, fuck, aghh, oh," moaned Amy.

My orgasm was building, I was so close. After a few more thrusts I started spurting cum deep inside her. I kept thrusting hard, short, brutal thrusts into her hot pussy. She hadn't noticed my cum inside her, and I was still rock hard. Desperate to make her come I increased my pace, fucking her harder and harder. I wanted Sarah to hear me make her wife scream.

"Harder, that's it, fuck me this is so good," Amy moaned loudly.

I started giving her pert bum cheeks a light slap. Each time, she gave a little whimper. I knew she liked spanking during sex, I'd heard Sarah do it enough. It then occurred to me that I hadn't thought about Sarah at all this time. Amy hadn't mentioned her either.

"Keep going Adam please, I'm so close," Amy shouted with hungry lust.

I was tiring now, my thrusts were slowing. With a Herculean effort, I mustered all my reserve energy. Hammering my cock harder and faster than ever before. The headboard was crashing into the wall denting the paintwork. Amy was screaming louder than ever, a primal animalistic wail.

"I'm cumming oh fuck I'm cumming, cum in me, cum in me, cum in," she screamed in rapid succession, in time with my swift thrusts.

I felt my lower body tighten as I unloaded inside her for a second time. I stopped trusting and collapsed sideways on the bed. Fatigue gripped me as I tried to control my breathing. Amy laid next to me, eyes closed, savouring her orgasm. She turned her head to me. Our faces were centimetres apart. She leant towards me and kissed me. I kissed her back, just a few light kisses. Her tongue snaked into my mouth. When I tried to suck it she pulled back sharply.

"Shit, we shouldn't have done that, that's not supposed to happen," Amy said a little flustered. She climbed off the bed and picked up her dressing gown.

"Don't worry, I wanted it too," I said as she looked at me nervously.

"It's ok, it's our little secret," she whispered putting a finger to her lips, opening the door to slip out.

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I woke up early in the morning to the sound of shouting. I couldn't hear exactly what was being said, but it sounded like Sarah. There was the sound of a slamming door and then silence.

Heading downstairs, I stopped in the doorway. Amy was sitting on a sofa in her dressing gown, knees pulled up to her chin, sobbing quietly. I went to the kitchen made a cup of tea, and sat down next to her.

"Do you want to talk about it?" I asked quietly, putting the mug on the coffee table.

Amy didn't respond, I waited a few moments and then made a motion to leave. Amy grabbed my arm to hold me back.

"What's up?" I asked again.

"Sarah thinks something is going on between us," Amy explained through sobs.

"Oh," I said not knowing what else to say. The tears were rolling down her face, blonde hair tied back in a rough ponytail. Even with watery, puffy eyes, she was very pretty.

"It's because we've been hanging out a lot, and the sessions have been lasting longer. I hadn't realised," she said picking up the tea and sipping it.

Now that she mentioned it, our sex sessions were getting longer each time. Sometimes we lay in bed a while before starting just talking, other times the foreplay went on a bit.

"I said at the start of all this it wasn't a good idea, Sarah used to hate seeing you with a guy," I said.

"Yer, but that was before we got together, and I'm not with you, we're just friends aren't we?" she asked.

I couldn't tell if she wanted an answer or not. I wasn't sure how I felt about Amy anymore. I had fancied her since I was a kid. She looked gorgeous, sitting there on the sofa. Long silky legs, beautiful teary blue eyes, strands of sunny blonde hair framing a pretty face. We had loads in common and got on so well. She was perfect girlfriend material. With everything going on between us I should be madly in love with her. I think a part of me was, but a bigger part was sad for her and Sarah.

"I'll have a chat with her," I told Amy softly.

She rested her head on my shoulder and snuggled in as I turned the telly on. If Sarah ever saw us sitting like this, I could forgive her for being upset.

I convinced Amy to go out that evening and let me speak to Sarah on my own. I had some dinner ready for when she got I'm home. She seemed surprised to see the table laid for just us two.

"Where's Amy?" she asked inquisitively.

"I thought it would be nice for us to have a meal together, maybe talk things out," I said diplomatically.

"Oh, she told you about this morning then, why am I not surprised," she said irritably.

Ignoring her tone I said "I think it would be a good idea if we went back to the clinic,"