[BluffTHIS!]

I don't like "trapping" with AA/KK out of position like that and would have reraised preflop. Had I just called like you I would have checkraised the flop as well. Regarding how you actually played it, the choices are he either has AJ/KJ and is testing you, a flush draw trying to inhibit a turn bet if no heart appears, or a hand that beats yours. I would probably call and lead the turn if no heart appears and see what he does. If he then just calls that, then there will be nothing other than a blocking bet left for the river. His reaction to a lead by you on the turn will probably provide the correct read on his hand in most cases, though AA probably would just call along behind.