"I know! I want to!" I reply, and head out. I usually put the things away in grill area up as I cook, and clean the grates right away, but today I had kept using cooking time to go peek at the ladies bodies in the pool, so it took a good 30 minutes to finish cleaning and getting everything put away.
My loss apparently, because Gina is zonked out in bed by the time I get inside to "back rub" her through to my satisfaction. I sit next to her and gently put my hand on her shoulder, giving it a slight rub. Maybe she's not fully asleep yet, I think. She barely moves, and her deep breathing gives away her actually sleeping, so I resign myself to no sex tonight.
I consider just going to bed, but playing with myself at the window, and the near naked wet female bodies today had me a bit on the horny side. I check the clock and it's almost 10PM. Sandy is surely asleep by now, so I head upstairs to my office/man cave, and notice that Sandy's bedroom door is closed and the lights are off. I quietly go into my office and close the door.
I set up the TV to be a computer monitor and start surfing for some porn to watch, and find a "mature" model that looks a bit like Sandy, and start to watch. I sit down, and start rubbing myself through my shorts, my thoughts turning to Sandy in her bathing suit today, about me cumming in the truck behind her, and the fantasy of walking out and stroking for them by the pool. I am fully hard, so I stand up and drop my shorts to the ground, and remove my shirt as I step out of the shorts. My cock is so hard and my hand feels amazing on it as I rub it up and down the shaft, feeling the head and rim with my thumb and forefinger in a ring shape, my left hand cupping and caressing my sack. I am teasing myself, and I can feel some precum leaking from the tip. I scoop it up with the tip of my forefinger and bring it to my mouth for a taste, before bringing my hand down to the shaft for a good pumping. As horny as I am, I know it is going to be a short session -- my dick is already aching for release. I lean back a bit and lift my pelvis up to get nice long strokes in, and to put a bit of pressure on my prostate by the clenching of my butt cheeks.
I am mid stroke when I hear the door open, and Sandy is at the door in her nightgown. I freeze, hand on cock, but have no where to hide what I am doing. I am trapped, and have no options but sit there naked.
Sandy starts talking, "Sorry, I saw the lights from under the door and thought maybe I had left..." and then she stops, "OH!" as she takes in the full scene of her son-in-law masturbating naked, hard cock in hand. I am torn, as I stare at the screen, not moving, and wonder if I acknowledge her or not, stop and cover up somehow, or ignore her and keep stroking. My mind first thinks "Cover up!" but I am so horny and my dick overrides the brain, and I choose the latter option. My hand starts moving up and down again, stroking my cock as if she isn't there. I am staring at the screen, but I can see Sandy start to turn away and close the door, when suddenly she stops. She turns back at me, and opens the door up again, facing me directly, never saying a word, just watching silently.
I cant believe my luck at getting my fantasy of being watched, so I make the most of it, and stroke away, and begin putting on a show of small upper thrusts as I stroke, getting my whole body into the game. My legs spread a bit wider as my strokes elongate to emphasize my cock moving up and down, in and out of my fist. My breathing is getting a bit shallow as I get more excited, and I let out a few small groans of pleasure to add another sense to the situation. I know I am approaching an orgasm, so I remove my eyes from the screen, and turn my head to look directly at her as I increase my pace.
It takes a few seconds, but she looks up from my cock, and we lock eyes. That is all I can take, and I begin to be vocal, throwing in "Ohs" and "fucks" and "yes's" between gasping breaths and groans. My hand is almost a blur as I stroke myself, staring at my mother-in-laws face while she watches. Finally, I can feel that moment, and I moan out "Oh Sandy!" and I drop my gaze down to my cock, leading her eyes down to it as well, right as the first spurt of white cum rockets out of my cock, landing on my chest. I lift my pelvis all the way up as the next few streaks of hot jizz eject themselves from my spasming cock and onto my belly.
I look up from staring at my cock erupting and look at Sandy again, and she is staring at my throbbing cock as it ejects my love seed, transfixed by the vision and the brazenness of my act, the utter lack of shame on my part as I self-gratify myself. I slowly squeeze out every drop of cum from my finished ejaculation, and as I release my cock, I use my finger to trace the pooling cum around my belly. Sandy moves a bit, as if she is going to leave, and I am feeling quite wanton, so for shock value, I scoop a bit of my sperm up with my finger and bring it to my mouth, staring at her face to see her reaction as I open my mouth and suck the cum right off it.
Her eyes widen a bit, and an "Oh My!" escapes her mouth in a whisper as she stops her turning away, so I do it again, bringing my finger down to my ejaculate, and then inserting that finger into my mouth as I perform mini-fellatio on my cum-drenched finger. I don't want this situation to end, so I continue this until I am no longer able to locate any more of my load to ingest. I lean back, and drop my hands to my side, and give a sly smile to her.
"Good night, Sandy. Sweet dreams." I tell her as she turns away and closes the door.