100nl flopped bottom straight, turn decision

[goofyballer]

SB is 33/0/2.0 over a ~40 hand sample, UTG is unknown.

Party Poker
No Limit Holdem Ring game
Blinds: $0.50/$1
6 players
Converter

Stack sizes:
UTG: $111.35
UTG+1: $85.94
CO: $69.51
Button: $179.92
SB: $90.75
Hero: $98

Pre-flop: (6 players) Hero is BB with 4[img]/images/graemlins/heart.gif[/img] 3[img]/images/graemlins/diamond.gif[/img]
UTG calls, 2 folds, Button calls, SB calls, Hero checks.

Flop: 7[img]/images/graemlins/heart.gif[/img] 5[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/club.gif[/img] ($4, 4 players)
<font color="#cc0000">SB bets $5</font>, Hero calls, UTG calls, Button folds.

<font color="blue">Too weak? I wasn't necessarily thrilled about my hand on this board; I mean, I liked it, but if I raised and got 3bet I would have felt pretty lost. So, I called.</font>

Turn: K[img]/images/graemlins/club.gif[/img] ($19, 3 players)
SB checks, <font color="#cc0000">Hero bets $15</font>, <font color="#cc0000">UTG raises to $30</font>, SB folds, <font color="blue">Hero with $77 left in his stack...shoves or folds, but I'm not sure which</font>

At this point UTG can't possibly have a flush draw; so, does he ever play this way with set/two pair?