Strange action in RR pot

[jessyj07]

the pfr is 57/30, the blind is 41/15, they are both aggressive postflop esp. considering how often they're in pots.

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP1 ($26.65)
Hero ($25.80)
CO ($5.60)
Button ($5.40)
SB ($7)
BB ($39.60)
UTG ($2.85)
UTG+1 ($17.05)

Preflop: Hero is MP2 with K[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/spade.gif[/img].
UTG calls $0.25, <font color="#CC3333">UTG+1 raises to $1.25</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises to $3.75</font>, <font color="#666666">3 folds</font>, BB calls $3.50, UTG folds, UTG+1 calls $2.50.

Flop: ($11.60) J[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets $4</font>, <font color="#CC3333">UTG+1 raises to $13.3</font>, Hero??????