Im dont think i would call that first bet on the flop unless i had seen UTG bet with nothing (or 88) [Edit: i will usually give someone the benifit of the doubt once and then watch more closely and see what they showdown before i risk my stack on this]. When Villain 2 comes over the top after i have already called once and then UTG calls it in done with the hand.
2 people all-in even at this level usually means that a single pair (even if it is Jacks) is no good.
As for why i fold i actually am not sure what UTG has but Villain2 i put on a possible set (or something that beats JJ) and fold.

Turns out i got them the wrong way around but i still think folding is right here even at 5NL.