One more..

[Kevin J]

1 limper and I raise with AA. sb calls.

Flop comes AJ3r. Checked to me and I bet. sb and limper call.

Turn is a T. Checked to me and I bet. sb check/raises, limper folds and I 3-bet. sb calls.

River is a 6 and I get check/raised again! My buddy who was watching this hand, said there's no way my hand was good. I paid off anyway and beat out ATo.

My question is, what was my opponent thinking? Did he check/raise the river (after I made it 3 bets on the turn with a straight and a better two-pair on board), for value or as a bluff? I think it was for value, but not knowing for sure is what makes me such a poor online player.