I fucked my sister in law, before she was my SIL 39M [MF] at the time I was 29.

Before my wife and I were married, we took a break for 3 months. During that 3 month span, she admitted to being with 2 guys. I was also with 1 girl and I’ve never shared this story with anyone. It was a one night stand….and it was with her sister, my now sister in law. I’ll call her M, my wife A. M is very attractive, blonde hair, blue eyes, white pale skin, she’s roughly 170 cm tall and 65kg, my guess anyways. A and M look quite different and both are good looking women.