QQ on K high flop, 3bet pot, line check (NL100)

[CalledDownLight]

Villain is unknown.

PokerStars No-Limit Hold'em, $1.00 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

saw flop|<font color="#C00000">saw showdown</font>

UTG ($45.05)
<font color="#C00000">UTG+1 ($53.75)</font>
MP1 ($86.15)
MP2 ($99)
MP3 ($91.60)
CO ($23.85)
Button ($99.40)
<font color="#C00000">Hero ($182.35)</font>
BB ($42.45)

Preflop: Hero is SB with Q[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">UTG+1 raises to $4</font>, <font color="#666666">5 folds</font>, <font color="#CC3333">Hero raises to $13</font>, <font color="#666666">1 fold</font>, UTG+1 calls $9.

Flop: ($27) 6[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $15</font>, <font color="#CC3333">UTG+1 raises to $40.75</font>, Hero calls $25.75.

Standard? Fold to flop raise? Check flop?