KK-weak tight

[phage]

This is my first hand post and from the way I played it you will see that I need to post and get help more often.
The villain seemed good but was relatively new to the table so no real reads. After this hand (and a few more orbits) I got the impression that he is a rather good thinking player. The reraise preflop made me think big pp (JJ/QQ/AA) or maybe AKs.
The c-r gave me fits...
How would you play this? Any help would be appreciated
(Oh and my raise to 3.5 was a bit of a mistake. Meant to make it 5)

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) converter

villain/ ($49.25)
MP2 ($46.25)
MP3 ($80.85)
CO ($10.25)
Hero ($61.20)
SB ($61.40)
BB ($17.70)
UTG ($36.35)
UTG+1 ($49.95)

Preflop: Hero is Button with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/club.gif[/img].
UTG calls $0.50, <font color="#666666">1 fold</font>, <font color="#CC3333">villain/ raises to $2</font>, <font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises to $3.5</font>, <font color="#666666">2 folds</font>, UTG folds, <font color="#CC3333">villain/ raises to $8</font>, Hero calls $4.50.

Flop: ($17.25) 8[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
villain checks, <font color="#CC3333">Hero bets $15</font>, <font color="#CC3333">villain raises to $41.25</font>, Hero ??
Results to follow.