Reply: Slutty SIL [F20] moved in with us

Me and my wife live in Chicago. I work from home and she is a nurse, working long shifts almost every day.
This year my SIL, Jill, moved in with us for college and to try to find some kind of intership. I had already heard the stories and rumours that she’s a little bit of a slut. But nothing could prepare me for what I would get to experience living with her.
So, my wife goes to work and I spend most of my time alone at home with Jill. I used to work from the other room, but now is her room. So I work right at the liiving room.
The thing is Jill is naughty. She likes to walk around the house in just a shirt and her panties. The low portion of her butt is always visible. And she never ever wears a bra. There’s not a single day I don’t get to see her pokies showing up in her mostly white shirts.
When I go take a shower, I usually live wrapped in my towel and go change in my room. It happenned about two or three times already - when I open the door to my room to put on my underwear, there’s Jill, laying in our bed, like expecting to catch a glimpse. I just take my underwear and head into the bathroom again to change.
But here’s what happenned that really got my blood flowing downstairs. She took a guy home the other day. I was laying in my bed, but I could hear everything. The walls are really thin.
I could hear the sloppy kisses, then it got sloppier.
Like really wet. She’s was blowing him. The wettest and most exciting blowjob I’m ever heard - I heard she was famous for that. It lasted a lot. I could her him moaning from getting his dick sucked by Jill.
After about 15 minutes, he penetrated her tight wet pussy. I could still hear that sloppy sound, meaning she was soaked. The bedsheets were soaked. She was dripping. I was already hard at this point, and started to feel myself to the sound of it. I had one of the best “alone time” sessions ever to the sound of my own sister in law getting her brains fucked out on the room next to mine. Just hope my wife never finds out.
And she moaned. Real. Loud. I could even say she screamed. Like she wanted me to hear, that’s crazy. The more she moaned the more I rubbed my cock. Unfortunately the guy didn’t last long, I don’t believe she came, but I sure as hell did. It was so hot to hear her begging for cock, begging to make her pussy full.
The bed was moving and hitting the wall. It was probably a rough fuck. She really gave her all. I imagine she was on top from what I could hear. Guess the guy couldn’t take much of that round fat ass going up and down his cock.
When it was over, the guy left. I put on some clothes and went to the kitchen for a glass of water. She was there, sweaty, lighting her cigarette. I couldn’t pretend nothing happenned, it would be awkward, so I said: “Tiring night, uh? Take a rest now”
She said “Tiring, but not worthy. I wish I could find someone to fuck me like you fuck Sara (that’s my wife)”.
Well, too bad I already fuck one sister. Guess she’s the lucky one. I never leave until I maker her cum. That guy was an asshole.