It's still cheating (as far as I'm concerned), but how much does it blur the moral line if it's cheating with the same sex: basically something the husband or wife can't possibly give them (or you)? Whether you would be the cheater or the cheater's sex partner, does it make it somehow more okay, or easier to rationalize?
It might make it easier to rationalize cheating for some people, but it doesn't "blur the moral line". Cheating is cheating. I was cheating just as much when I let a guy suck me off (or I sucked him off) as when I was with other women. The fact that my wife doesn't have a cock for me to suck doesn't mean I get to go around behind her back sucking cocks. If I want to go full on bisexual and not be a "cheater", I would have to come clean with my partner about it and probably end the relationship (unless, by some miracle, she consented to making our relationship "open" in some way).
Its cheating & I avoid men who want to go this route. A lot of them claim their marriage is open, but you;ll never be able to talk to the partner. Always a excuse why not.
On a trivia note. I have run across a woman who wanted to cheat on her lesbian partner with a man.
The first guy I slept with was married to a woman but I didn't know that till after. I am not saying it would have stopped me but it is not something I would do if I were in a relationship. If you are not happy then end the relationship it's only fair
