Your preflop play was a little loose, but if you don't hit you can fold, while if you do hit they won't see it coming.

I don't like you leading out on the flop. In most low-limit games (especially those on Party), pre-flop raisers invariably bet the flop, so this may have been a good chance to get a check-raise in there. You not only would increase the size of the pot, but also force BB to call 2 bets cold if he wishes to continue.

I like your decision to 3-bet the turn and simply check-call the river after MP1 caps the turn. Given the fact that MP1 called 2 bets cold preflop, MP1 is very likely to hold one of the hands that beats you (KT, QT, TT, QQ, KK, AJ), but you can't be sure. After MP1 capped the turn, I would suspect that you are beat, but since you're getting 19-1 on your call, you can't fold on the river, so your check-call was the right play there.