AK, opponent wierd line

Party 3/6, 9 handed, Hero is button with A [img]/images/graemlins/diamond.gif[/img]K [img]/images/graemlins/spade.gif[/img],
UTG calls, folds to hero who raises, both blinds fold, UTG calls. Heads up to the flop:
K [img]/images/graemlins/heart.gif[/img]3 [img]/images/graemlins/spade.gif[/img]9 [img]/images/graemlins/diamond.gif[/img]
UTG checks, Hero bets, UTG raises, Hero calls with intent of raising on the turn:
Q [img]/images/graemlins/diamond.gif[/img]
UTG checks, Hero bets, UTG raises??
First, what do you think of the smooth call on the flop? Should i just go ahead and three-bet? Also, now that I've been raised on the turn, should I go ahead and three bet here or just call planning to call down?