I was the "side piece" with a woman I met about five years ago. Her husband wasn't able to get it up and wasn't interested in fixing it, so she went outside the marriage to have her needs met. It was my first experience outside of a traditional monogamous relationship and it definitely broadened my horizons. And it was such an ego boost when she'd be on her knees polishing my wand, then look up at me and tell me how much bigger and harder I am than her husband. I didn't realize until she blurted it out unprompted how much of a turn-on it was to hear her shit-talk her husband while I was inside her. She was responsible for what is still to this day the best sex I've ever had.
I'm now in a poly relationship with my girlfriend. While I don't enjoy cuckolding, I do enjoy hearing about her fucking other guys from more of a hotwifing perspective. I enjoy seeing her taken care of, even if it's not with me. She'll come back home and hop into bed with me after a night of getting fucked by another guy, his cum still seeping from her pussy, and she'll hop on my cock and tell me how big his cock was and all the positions she got fucked in. I don't feel an ounce of jealousy, which I'm thankful for because it lets me enjoy my sex life uninhibited.