The common romantic view among those in the Cancer sign is "want to date someone they love enough to marry," so it's unimaginable for them to cheat even when they have a girlfriend. They tend to be dedicated to their true love and strive to always be a sincere boyfriend. They should politely decline any advances from anyone.

If a Cancer man were to cheat, it might not end with just an affair. There could also be a potential for a change of heart and discussions of splitting up. Particularly, he might be drawn to a woman who listens empathetically to his concerns, even those that his girlfriend may not be interested in.