If my wife wanted me to please her boyfriend, I'd gladly suck his dick and either swallow his load, or let him cum all over my face. She doesn't like cum in her mouth or on her face, and I DO, so it could be a win-win for everybody.
He's also borderline obsessed with wanting anal sex with my wife, even though wife ISN'T interested in receiving anal sex from him or me. I on the other hand... I'm bisexual, and a submissive bottom with men. I'd happily give him my ass to use whenever he's in the mood for anal sex.