you have cheated on your wife with her sister.

her sister has developed a deep crush on you..like for example every time you visit your wife her sister always greets you first, and she seemed to always get close and talk about her feelings..and how she wants too be "closer" too you.

you kinda developed feelings for her also..but you didnt wanna tell your wife because yk she would be pissed, you guys made love and everything.

"This is so wrong..but it feels good.." *your wife sister says