AK, worth getting stacked?

[jkkkk]

villain is classic TAG, not too agressive though 2.5 pfr, 3avg ag

Party Poker (10 handed) converter

Preflop: Hero is CO with A[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/club.gif[/img].
<font color="#666666">8 folds</font>.

3 or so limps to Hero who raises to $2, one caller who is UTG+1.

Flop: 2[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
.
UTG+1 bets $5, I call.

Turn: 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>

UTG+1 bets $15, I fold.



I know this line is weak, I think I should of raised the flop to see where I was. Raise to $15?