Listening through the door`

"Ungh!... Ungh!... Ahhh!... Ahhh!...Yesss!... Fuck me!... Yesss!..." Diane's voice carries through the door. A satisfied smile spreads across your face as you listen to Alex plow your sister. Of course you would rather be the one being plowed right now, but at least you won't have to worry about her trying to seduce your husband behind your back. Knowing Alex and his magnificent French cock, she should be satiated for weeks. Besides, you feel a little guilty about fucking her ex-husband last night, so setting her up to finally get stuffed to her heart's content by Alex also helps to soothe your conscience.

"Mon dieu, you are insatiable!" Alex exclaims as he continues to thrust. "Much more so than our last rendezvous, ... Ungh!... if I may say so."

Last rendezvous? That little slut already fucked Alex before and never told you about it! You should be upset, but listening to them fuck each other senseless has really gotten you turned on.

"Oooh!... Let's just say... Aaah!... divorce has been good for my sex life... Oooh yes!... Yes!... Harder!"

So Diane was having an affair with Alex while she was still married to Steve, and she never told you about it? Who else has she been fucking?

"Unh!... Unh!.. so I see. Unh!... And the lucky man who bedded you last night? He was good, no? Unh!... A Frenchman can tell these things."

Wait a minute. Didn't Dave tell you on the phone yesterday that Diane came over for dinner? Maybe she hooked up with someone else afterwards. Maybe Alex is mistaken. You know he's not though. Alex could always tell when you fucked someone the night before.

"Oh yes! He was incredib... Oh!... Alex!... I'm cumming! Aaah yes! Yes! YES! FUCK YES!"

You're not sure what to think as you listen to your sister's screaming orgasms. Did she sleep with Dave last night? There's almost no doubt in your mind now that she did. A range of emotions run through you as you hear them coming down from their mutual climax. You go from stunned to angry to hurt to aroused and back around again before you finally settle on feeling...