Villain is laggy 33/25/2.8

He opens in the CO, I 3-bet Qd Jd in SB, he calls

Flop: Ad Th 7h I bet, he raises, i call,

Turn: 6h check, check

River: Jh, Hero???

I´m not quite sure what his turn check means. Normally he is aggressive enough to bet the turn with any Ace.
c/f the river seems a little bit too weak against this guy
but i really dont see any hand I can beat....