I ended up fucking my wife's sister. My wife was a sweet girl but not the type to drink or stay up late. We started kinda arguing about it until one night she kinda half joked I should start just hanging out with her sister. Well, that's exactly what I did and we started with mild flirtation, to me worshipping her feet and handjobs/footjobs, to straight raw fucking and deep, passionate kissing. I ended up more in love with her sister than my wife. Was a beautiful time of my life and I still get hard just thinking about it.