A tl;dr for those starting here. My ex-wife Ellen is pregnant, and it's mine. We had sex as a part of a fivesome with my wife Shelly and a couple of friends. She and my wife came up with a plan for us to support her during pregnancy and infancy, in return which she and I will support Shelly when she has a child immediately afterward. Financially, that turns out to mean we may all live together for two and a half years at minimum.
We spend an evening negotiating the deal, and now we're sealing it with sex.
My ex- Ellen lay limply on the bed, catching her breath as my wife Shelly gently nuzzled her crotch, running her nose through the light brown curls. I'd pulled my thumb out of Ellen's ass and got up to go wash my hands.
When I came out of the bathroom, Ellen had moved up the bed so her head was on the pillows and had her knees up and legs spread as Shelly was actively eating her pussy. Ellen was watching her, face slack with pleasure, but eyes bright with clear desire.
She looked up and saw me, half erect, walking out of the bathroom.
"Fuck her while she eats me. Fuck her and cum in her. I want to watch your face."
I was suddenly fully hard. I started to say "Twist my arm..." but instead said "Of course...if that's what you want..."
Shelly pulled her ass up so she was on her knees without pulling her face away from Ellen, and I stopped to admire the view.
Perfect upside down heart-shaped ass, legs muscular but so slender that she has a thigh gap. Red inner pussy lips that extend far past the outer ones, even when she isn't aroused. When she is -- and she was right now -- they grew even longer and thickened, and the deep color became a bright red. When erect, her clit was as big as the first joint on my little finger, and I could see it, shiny pale pink as it swelled past the shield of its hood.
There were drops of her fluids glistening at the edges, and as I moved onto the bed, she pushed her ass back to me I took my fully erect cock in my hand and knelt behind her and rubbed the head on her lips for an instant to wet it and then slowly pushed deep into her. I heard her groan as I did, and Ellen arched her hips up in pleasure.
I had to remind myself to make slow movements because I really wanted to start slamming into her -- she was so wet and swollen and open to me. I slid in and out trying to balance my pleasure and Shelly's and the pleasure she was obviously giving Ellen.
Ellen started making noises and grabbing Shelly's head, and so I just pressed myself as deeply into Shelly as I could and felt the smooth hardness of her cervix at the tip of my cock, which made both of us moan.
Ellen started talking. "Oh yes, ohh...ohh....ohh, fuck, yes....oh!!" and her hips rocked and her legs shook as she squeezed her own breasts hard as she came. Shelly held up her hand to signal 'five' and I laughed. She did too, which made her squeeze my cock and suddenly I felt the stirring in my balls and started pushing deeper into her and then felt the pleasure rise as I shot cum into the very back of her pussy.
Sometimes I can make the orgasm last longer by only making little movements in and out when my body really wants to slam deeply in and out, so I did that until the pulsing died off and then hung my head and caught my breath.
I heard Ellen ask "Is he still hard?" and Shelly giggle and say "Oh yes." The little squeezes from her giggling had ended that question, and I was fully erect inside her.
"OK, Shelly. You get up here. I want to eat his cum out of you. Van, let's see what you can still do with that."
She reached down and pulled Shelly up her body, ending with her knees just below the pillows and her hands on the headboard. Being eaten that way was one of her favorite things, and by random chance, Ellen had decided that was what she wanted. Then I saw a drop of white cum dripping down and realized that eating my cum out of someone's pussy was one of Ellen's favorite things. Events had conspired to give each of them what they wanted.
And, as I moved between Ellen's open legs, admiring the thin light brown curls damply plastered over the swollen pink slit between her lips, I realized I was getting it too.
I'd cum twice, so know it'd take me a while to do it again. Shelly was excited as hell, and getting her favorite pleasure, but so was Ellen. The question was who was going to get off first.
Shelly slowly lowered herself to Ellen's waiting mouth and I saw Ellen's tongue lap up the drops hanging above her and then as Shelly put her pussy on her, I saw Ellen's jaw working as she scoured Shelly's pussy with her tongue.
I was still wet with Shelly's juices, so I just pushed the tip into Ellen and slid the whole way in. She arched her back in response. I felt her and suddenly thought about how exciting and forbidden it felt to fuck her in Boulder. She liked to be railed sometimes, so I just started driving in and out as hard and quickly as I thought I could maintain. In a few minutes, I was starting to get winded, and as I slowed down I watched as Shelly's back muscles suddenly stood out in sharp definition as she tensed up and then I saw her ass shake as she moved her clit over Ellen's tongue and then was still.
Ellen and I were heading to our peaks and as I felt her pussy clench in random spasms around me, I growled and suddenly shot three ropes of cum into her and then pressed myself deep into her as she bucked under me and let the sharp pulses of the aftershocks drive the final drops into her as her aftershocks gripped me.