All I see are red flags OP. Even if you guys are remaining "friends", he's clearly shown that only does he not respect you, and relationships, but he also does not respect his new girlfriend. Is that really someone you want to friends with? Let alone in a relationship with? He's already proved you can't trust him once, don't let him make it a third time. Take it from someone who knows, keep your distance and work on yourself, this will only end badly in the long run with your feelings and most likely his current girlfriends hurt as well.