NL 100 Laying down top pair on a 3-flush flop

[rjacobs003]

Sounds ok from the title but any thoughts on this play. Have no reads on the villian. He's been at the table or 5 hands and seems aggressive.

PokerStars No-Limit Hold'em, $1.00 BB (9 handed) internettexasholdem.com

Hero ($153.55)
UTG+1 ($99)
MP1 ($20.50)
MP2 ($19.50)
MP3 ($107.10)
CO ($46.90)
Button ($14.20)
SB ($107.60)
BB ($87.80)

Preflop: Hero is UTG with Q[img]/images/graemlins/spade.gif[/img], K[img]/images/graemlins/diamond.gif[/img].
Hero calls $1, <font color="#666666">3 folds</font>, MP3 calls $1, <font color="#666666">2 folds</font>, <font color="#CC3333">SB raises to $4</font>, <font color="#666666">1 fold</font>, Hero calls $3, MP3 folds.

Flop: ($10) J[img]/images/graemlins/heart.gif[/img], K[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">SB bets $6</font>, <font color="#CC3333">Hero raises to $15.5</font>, <font color="#CC3333">SB raises to $30</font>, Hero folds.

Final Pot: $55.50

[Vegetarian]

I really hate your flop raise. It is to small to get AA or AK to fold and no worse hand is really ever calling it, except for hands your basically 55/45 against. And when you are called you are going to have a very difficult time making correct decisions on later streets.

As played it is obviously an insta fold.