I've been married to my wife for 23 years. In the beginning our sex life was fantastic and over the years it diminished after having kids and all that. That part I can understand to some extent. But for the last 10 years our sex life has diminished to nothing. She always comes up with excuses to avoid being together, even when we were alone. We haven't had sex in well over a year.
A few years ago I ended up having a very brief fling which she found out about.