25NL: TPTK Vs sudden aggression

[RapidEvolution]

PokerStars No-Limit Hold'em, $0.25 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

MP1 ($29.25)
MP2 ($18.80)
Hero ($31.80)
CO ($24.05)
Button ($15.35)
SB ($23.55)
BB ($14.25)
UTG ($24.15)
UTG+1 ($45.60)

Preflop: Hero is MP3 with T[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/spade.gif[/img].
<font color="#666666">2 folds</font>, MP1 calls $0.25, MP2 calls $0.25, Hero calls $0.25, <font color="#666666">1 fold</font>, Button calls $0.25, <font color="#666666">1 fold</font>, BB checks.

Flop: ($1.35) T[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/club.gif[/img], 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(5 players)</font>
BB checks, MP1 checks, MP2 checks, <font color="#CC3333">Hero bets $1</font>, Button folds, BB folds, MP1 calls $1, MP2 folds.

Turn: ($3.35) 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets $0.25</font>, Hero calls $0.25.

River: ($3.85) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">MP1 bets $14.5</font>, Hero?



I call the turn even though I know he's trying to price himself in. I don't have a very strong hand, and my investment here is small. The river bet is weird and I think it's either a weird 7 or missed draw. Not sure I wanna call here but....what do you do?