Granted I haven’t been around the dating pool very often but from what I’ve seen of cheating it’s rarely because the person is interested in polyamory but because they are simply normal and are trying to take advantage of one aspect of a relationship and fulfill their other desires with a different relationship for example taking advantage of husband A being rich and take advantage of husband B because he’s physically hot both are being taken advantaged of and husband A feels like he’s nothing more than a wallet and husband B feels like he’s nothing more than a dick on top of all that in the US the family court system very heavily favors women so if a girl is not 100% interested in a man it’s quite possible for the man to loose his entire lively hood I will admit this is a pretty male centric take but like I said i haven’t been paying much attention to dating world and i only have the perspective of a man