Two pair from BB?

[Nybster]

What do you do when you flop 2 pair from BB?
I seem to always be afraid of sets. Since I often limp with any PP I figure many others do the same, and hence I don't like playing hands with no raise PF. But on the other hand it seems like a waste to muck 2pair on the flop, and who the xxxx plays a set like this? what do you think?

Anyway, this is a HH from such a situation I was in today.

Party Poker No-Limit Hold'em Tourney, Big Blind is t30 (10 handed) converter

UTG+2 (t988)
MP1 (t1150)
MP2 (t1570)
MP3 (t1035)
CO (t885)
Button (t1393)
SB (t394)
Hero (t980)
UTG (t810)
UTG+1 (t795)

Preflop: Hero is BB with 9[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/diamond.gif[/img].
UTG calls t30, <font color="#666666">3 folds</font>, MP2 calls t30, MP3 calls t30, CO calls t30, Button calls t30, <font color="#666666">1 fold</font>, Hero checks.

Flop: (t195) 3[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/diamond.gif[/img], 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(6 players)</font>
<font color="#CC3333">Hero bets t90</font>, UTG folds, MP2 calls t90, MP3 folds, CO folds, Button raises t1363 (all-in), Hero folds, MP2 folds.

All comments on play appreciated!