50 NL Party Hand

Just opened up a small account on party to test the waters (Im a pokerroom regular). An interesting hand came up and im wondering if there was a better way for me to play it. On the flop I think my call was ok, as I was pretty sure I was going to be raised off the hand if I put in a re-raise. No reads, I had just sat down.

Party Poker (9 handed) converter

Preflop: Hero is BB with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/diamond.gif[/img].
<font color="#666666">MP5 calls t.50, SB calls t.50, Hero raises t2, MP5 calls t2, SB calls t2 </font>.

Flop: 8[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/diamond.gif[/img], T[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
MP5 checks, SB bets $4, Hero calls t$4, MP5 folds.

Turn: 6[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
SB bets $9, Hero raises t$18, SB raises t$31, Hero calls t$12.75 and is all in.
River: 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>

Final Pot:

Results in white below: <font color="#FFFFFF">
SB has Tc Td (three of a kind, tens).
Hero has 9h 9d (straight, ten high).
Outcome: </font>

First, what hands do you possibly think the SB is betting on the flop?

Second, what is the Hero's action on the flop?