Most Helpful Guy
He is most likely trying to hook up with you, despite him seeming like he is not that kind of guy. A good girl will do a lot of crazy things to a guy, especially to young guys. It may not just be a hook up thing though, he may genuinely like you, and he could have been jealous of his friend the whole time you two were dating. Who knows.
But the reason a guy in a situation like that reaches out to a girl is almost always because he likes her.