I have been licking the cum of other men out of my wife's used pussy for years. I do not do it because I enjoy the 'taste' of my wife's pussy combined with the cum of various different men. I do it because it is so taboo and also because my wife loves it when I lick her clean. Kate says that me eating her pussy after other men fuck her is the nastiest thing she has ever experienced and she loves it. She can't stop cumming when I eat her after she has been fucked.
Kate's please in the situation is paramount, but for me, it is all about me reveling in the fact that I have a pretty suburban wife and mom who likes to spread her legs for other men and let them fuck her bare and pump their cum in her cunt. The taste and scent of her pussy after other guys fuck her is different with each guy but I hardly notice any of that. My cock throbs because my loving wife let some other guy enjoy her pussy and I am participating after the fact.
Most of the time, the guys fucking Kate are friends of ours, usually, married guys we know, and I am there watching and stroking my cock. When they cum in Kate, I get between her legs and lick and suck their cum out of her in front of them. Most of them get hard again right away watching me eat their cum and seeing how much it pleases Kate.
Kate sometimes has sex with other guys alone, usually guys I have never met, but when she comes home I eat their cum out of her pussy while she tells me about her evening. I find it very erotic to taste the cum of guys who have fucked my wife and I have no idea who they are.
I always jerk off when watching other men enjoying my wife in bed, or when I know that Kate is out getting fucked by someone I don't know, but I always wait to cum until after I have licked her pussy clean. Once I cum, I do lose interest for a while.
Happy to answer any questions.