30-60 with a player that always gives me trouble

[lil']

My opponent is loose and very aggressive, but I think he's very good, and he is one of the few players that gives me trouble. Every time I watch him play, he always seems to be raising, and he puts a lot of pressure on his opponents.

This was Pokerstars 30-60 5 handed, but I don't have the hand history.

He open raises from UTG, I three bet with A-Ko. Everyone else folds and it's heads up.

The flop is K-J-X rainbow. I bet and he calls.

The Turn is an offsuit 9. I bet he check raises. He always does this. I decide to three bet. He calls me down when I bet the river again, and I lose to J-9o.

Bah. Maybe I shoulda just called down.