In my opinion I think it depends on what specifically they find arousing about cuckold porn

Like if a man is getting off to cuckold porn because he finds the men and the woman in the video sexually attractive then I think he's bisexual.

But if a man is just getting of to the humilation aspect of seeing a hot domme wife physically force her cuck loser husband to suck her lover's dick for her than I don't he's bisexual.

Because I believe in order for someone to be bisexual they have to find both men and women attractive. But that's just my opinion what do you guys think?