Line?

[Drontier]

Party Poker 10/20 Hold'em (6 max, 6 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is Button with Q/images/graemlins/diamond.gif, T/images/graemlins/heart.gif.
UTG calls, <font color="#666666">2 folds</font>, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, BB calls, UTG calls.

Flop: (6.50 SB) 8/images/graemlins/spade.gif, T/images/graemlins/spade.gif, 5/images/graemlins/spade.gif <font color="#0000FF">(3 players)</font>
BB checks, UTG checks, <font color="#CC3333">Hero bets</font>, BB calls, UTG calls.

Turn: (4.75 BB) 3/images/graemlins/heart.gif <font color="#0000FF">(3 players)</font>
<font color="#CC3333">BB bets</font>, UTG calls, <font color="#CC3333">Hero raises</font>, <font color="#CC3333">BB 3-bets</font>, UTG calls, Hero folds.

River: (12.75 BB) 5/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
<font color="#CC3333">BB bets</font>, UTG folds.

Final Pot: 13.75 BB

[wheelz]

I don't you think you could be faulted for calling down an unknown, but it looks like a good fold to me.

[einbert]

The BB played his hand beautifully, assume he has what I put him on (a flopped flush or set).

Your line is perfect as well. I wouldn't call down, there's a decent chance you have the third best hand and there's also a very good chance you're drawing totally dead.