If Curse was a woman fucking a married guy or a guy fucking a married woman, that would be a little different, though I'd be in no position to judge. But he's a dude fucking another dude who's married to a woman. The dude wants dick. Presumably he isn't going to get that from his wife. It's either a strapping young man like Curse or male hookers.
being gay isn't just about dick. he
could get anal stimulation from his wife, it could even be hot and wonderful and plenty of dudes are into that, but he likes guys. She probably doesn't turn him on.
And it's probably just as bad to lose your husband to a man. She may not get violent with you like the other guy would in a man or wife cheating on the other situation, but a happily married woman with children? She's probably gonna be fucking devastated when she finds out her husband is gay.