0.5/1: A flopped top set gets plenty of action, too weak?

[Jackrabbit Slim]

Been at the table an orbit or two so my lame self has no real reads. So I flop my set but the board looks great for straight draws so I bet and get some serious resistance from UTG+1. When he keeps raising on the blank turn I'm starting to see that flopped straight after all and slow down. Although J8 isn't that unlikely for a limp at this level, a lower pocket pair seems almost more likely, especially since Button most likely had some of the straight filling cards. Should I keep jamming the pot on the turn/river here or is the ghost I'm seeing likely?

Party Poker 0.50/1 Hold'em (8 handed) converter (http://www.selachian.com/tools/bisonconverter/hhconverter.cgi)

Preflop: Hero is BB with T/images/graemlins/heart.gif, T/images/graemlins/club.gif.
<font color="#666666">1 fold</font>, UTG+1 calls, <font color="#666666">3 folds</font>, Button calls, <font color="#666666">1 fold</font>, <font color="#CC3333">Hero raises</font>, UTG+1 calls, Button calls.

Flop: (6.50 SB) T/images/graemlins/spade.gif, 9/images/graemlins/diamond.gif, 7/images/graemlins/heart.gif <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG+1 raises</font>, Button calls, <font color="#CC3333">Hero 3-bets</font>, <font color="#CC3333">UTG+1 caps</font>, Button folds, Hero calls.

Turn: (8.25 BB) 2/images/graemlins/spade.gif <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG+1 raises</font>, Hero calls.

River: (12.25 BB) 5/images/graemlins/heart.gif <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">UTG+1 bets</font>, Hero calls.

Final Pot: 14.25 BB

[Kumubou]

Three-bet the turn. You lose to two hands: J8 and 86. He could very well have a lower set or two pair. I figure you are good here way more than ~25% of the time (on top of the ~25% equity you have even if he tabled his straight). Now if he caps the turn and the river does not pair the board, I just call. (If he just calls your turn 3-bet, bet out.)

-K

[davelin]

3-bet turn.