Not simply a man who's
wife/girlfriend cheats on him, but rather a man who actually gets aroused by knowing or seeing her in sexual situations with other
men, such as
flirting, kissing, fondling, or sex. In particular, situations where he is NOT participating but instead marginalized, just observing, or even completely ignored.
You should have seen Frank smiling as his wife was flirting with other
men at the club, even allowing them to grope her; I swear it was giving that
crazy cuckhold a
hard-on.