A person is either a cheater or not a cheater, it's as easy as that. A guy who claims to not typically being a cheater, and then cheats because a woman "opened a door" for him by dating him, is a guy with very low self-esteem and lots of insecurities, who couldn't handle being successful in dating. But regardless of what he looks like and how be feels about himself, he's a cheater by definition. All the rest are just excuses to justify the cheating.