77, flopped bottom set close to bubble

[paddymcg21]

Deepish in a small stakes MTT (Absolute 4k guaranteed). 48 left with top 45 cashing. Average stack 35k roughly. Blinds 600/1200. UTG+1(quite active and aggressive, around 70k in chips) raises to 3,600, folded to me in the CO (I have 52k) and I have 77. I decide to smooth call. Button (has around 35k and is quite tight) also calls, blinds both fold.

pot is 12,600
Flop comes 7s Qs Jd

UTG+1 leads for 5k I re pop it to 15k, button shoves his last 30k or so in and the original raiser shoves his entire stack all in. What are people thinking here?? Am I calling this?
cheers in advance
Paddy