He likes you over her, (slightly),
but he would rather be with her than you if you are going to be super dramatic about it.
And he isn't "committed" to either of you. He is a player.
He doesnt really love either of you, he is just in it for the fun right now. He isn't like trying to settle down, get married, and have kids. And depending on your age, that might be the normal/smart attitude for him to have, idk. It depends how old y'all are.
Either way, you shouldn't be trying to get this guy back. He might find you more attractive/fun than his ex as a whole, but he clearly isnt dedicated to you enough to be faithful. He definitely still wants to cheat. And he didnt apologize, so he doesnt respect you a ton either. He doesnt respect her either though, bcuz for him to make her a dirty little secret shows he doesnt respect her either. He is just using both of you. He might like you slightly more than her, but still, neither you nor the other girl should be proud of your interactions with this guy. He's a sleazeball at the moment at least. He may grow up in 10 years, but not today. Not anytime soon. DONT WAIT AROUND. Find someone else. And in the meantime, focus on your career, your physical health, your fitness, your education, your female friendships, etc