Yes. Wish my wife was into it. Before I was married I shared several cocks with married couples
The fantasy is that I have no choice in the matter - a controlled, bi-cuckold...or...my partner (and possibly other women) get off watching, as I am ordered to humiliate myself for their viewing pleasure.
Maybe by partner and I played some sort of game where the stakes are, loser must do whatever the winner desires as a reason for being in that position. It's not something I'd do by choice, yet I could really get off on it if a woman (women) got really turned on by it.
First off my wife would never go to bed with another man. I have had a fantasy where she comes home with a guy and they go upstairs. I hear them bathing each other and go upstairs to find her and him going naked into the bedroom. She sees me and tells me to bath if I want to join in. When I get out of the bath and walk into the bedroom she has her legs spread wide and I watch as his large cock is going in and out of her. My wife gets on all fours and tells me to get under her a lick her clit. In the process I also suck on his cock and balls.
I would and I have. It started with licking my then girlfriend’s clit as she sat on his cock in a reverse cowgirl on the couch. I licked his cock really well, then cleaned them both once he came. He was about 9” long, several inches bigger than me. She and I also licked his cock together and I sucked him to completion. I did swallow. He sucked me as well, but I couldn’t cum. The feeling of his beard stubble on my thigh was too disconcerting.