[AMadison]

UTGs play might not be what most would call intelligent or good poker play, but that doesn't mean we should assume he can't have a big hand and just not played it optimally. I think UTG screams JJ (or possibly 55, AA) here.
Since he is an unknown we cannot conclude the value of his cards because his play doesn't look "normal". But think how he could be justifying every bet he makes here with a hand like JJ or 55.

PF: He tells himself something like this "I have a good hand, but I don't want to put to much into the middle in case over cards hit. (or in the case of AA I don't want everyone to fold and me only win blinds)"

FLOP: He tells himself "I hit a SET! I need to get paid off! I'll check raise!" So he checks, and hero bets. Then it comes back to him and he says "I don't want to scare him off completely. I need him to not fold his flush draw" so he min raises and lays good odds to call the draw.

TURN: "I didn't expect two guys to come along.... I need to protect my hand now and not let someone draw out on me cheap...All IN!"

And despite the "poor" play from the UTG, this pretty common line of thinking has just justified every bet he made and been consistent with the thoughts of a weak tight player trying hard to not be weak because he read it in a book somewhere.

MP looks like he is drawing with something like QTs+ drawing to a flush and a straight thinking "If 2 people are going to come along I am getting great odds to draw".

I fold, expect UTG to have a set almost every time and see the cards get turned up and now UTG isn't as unknown.