My Head Asploded

[Equal]

I spike my set on the river, then out of nowhere, ACTION!!

$10/$25 No Limit Holdem
6 players

Stacks:
UTG (<font color="#0000cc">$1409.15</font>)
Hero (<font color="#0000cc">$3124.00</font>)
CO (<font color="#0000cc">$660.00</font>)
BTN (<font color="#0000cc">$2940.00</font>)
SB (<font color="#0000cc">$5490.50</font>)
BB (<font color="#0000cc">$953.00</font>)

Pre-flop: ($35, 6 players) Hero is UTG 1 8[img]/images/graemlins/spade.gif[/img] 8[img]/images/graemlins/club.gif[/img]
<font color="#cc0000">UTG raises to $50</font>, Hero calls $50, 3 folds, BB calls $25

Flop: 3[img]/images/graemlins/spade.gif[/img] 9[img]/images/graemlins/heart.gif[/img] A[img]/images/graemlins/club.gif[/img] ($160, 3 players)
BB checks, UTG checks, Hero checks

Turn: 5[img]/images/graemlins/heart.gif[/img] ($160, 3 players)
<font color="#cc0000">BB bets $25</font>, UTG calls $25, Hero calls $25

River: 8[img]/images/graemlins/diamond.gif[/img] ($235, 3 players)
<font color="#cc0000">BB bets $235</font>, <font color="#cc0000">UTG goes all-in $1334.15</font>, <font color="#0000cc">Hero?</font>

BB is unknown short stacker that just sat, UTG is guy Ive played before that my notes say "called pf rer w QT" and "called 3 barrels with top pair"... so donkish tendencies, but I dunno if he's decent or not.

I didnt reraise pf because of his shortish stack.

So now what?