I can't see him calling that flop without an overpair or a set. Then he bets out on the turn acting like he has a set. Then he gets aggressive on the river acting like he has a boat. I play too tight at times but this may be the time to fold your aces.

How loose is this guy?

I don't get the re-raising and the betting out on the turn with 5-6 suited. But, yes, a re-raise on the turn may have gotten him to lay that down.