flop trips, we're 3 handed: go fast or go slow?

[SpleenLSD]

Florida B&M. 1-2NL, max $100 buy-in, with a $2 blind on the button (cardrooms are now taking a $2 rake on $5, so the extra blind equals a drop), 9 handed.

I've been sitting for maybe an hour. No real reads on anyone but I've noticed UTG has yet to play a hand. As far as my play so far I've been in one hand so far where I called a MP PF raise on the button with 88, heads-up, semi-bluffed at an Axx flop and MP mucks QQ face up. Nine hands later...

Effective stack is $100. I'm maybe $140. No one over $225.

Hero is Button with 7[img]/images/graemlins/club.gif[/img], 7[img]/images/graemlins/spade.gif[/img]. UTG likes $15, MP+2, CO and I call. 4 players, $63 pot and the flop comes down:
Flop: J[img]/images/graemlins/diamond.gif[/img], 7[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/diamond.gif[/img]

UTG leads for $25, MP+2 folds, CO calls, Hero...?

So, now that I've got a set and there's $113 in the middle (I have about that in front of me) is this the time to get it in, or go slow and try to get value from both players on later streets? I feel like UTG is AK or maybe a bigger pocket pair, CO could be anything, so I can't rule out the possibility that JJ or 2 diamonds are in someone's hand. My knowledge of either player's range is pretty weak here. Also, at this point I'm second guessing the PF flat call, if only because a raise there would have made my flop decision much easier. Thoughts?