Easy fold of pocket rockets on the river?

[SackUp]

Ok, I don't know how else I could have played this hand but it really irks me.

Did I slow down too soon?

This fold standard?

UTG+2 is 21.9/4.49/1.15
CO is an unknown

Party Poker 2/4 Hold'em (10 handed) converter

Preflop: Hero is SB with A[img]/images/graemlins/heart.gif[/img], A[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">2 folds</font>, UTG+2 calls, MP1 calls, MP2 calls, MP3 calls, CO calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, BB calls, UTG+2 calls, MP1 calls, MP2 calls, MP3 calls, CO calls.

Flop: (14 SB) T[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(7 players)</font>
<font color="#CC3333">Hero bets</font>, BB calls, <font color="#CC3333">UTG+2 raises</font>, MP1 folds, MP2 folds, MP3 folds, CO calls, <font color="#CC3333">Hero 3-bets</font>, BB folds, <font color="#CC3333">UTG+2 caps</font>, CO calls, Hero calls.

Turn: (13.50 BB) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">UTG+2 bets</font>, CO calls, Hero calls.

River: (16.50 BB) T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, <font color="#CC3333">UTG+2 bets</font>, <font color="#CC3333">CO raises</font>, Hero folds, UTG+2 calls.

Final Pot: 20.50 BB