[sirana]

grunch

you won't be able to protect your set by raising on the flop because 3 of the 5 people you are protecting against are between you and MP2. the flop raise is still good imo, since it is a decent value raise and you got MP1 to MP3 cornered for two bets.

I think the turn raise is a mistake but not a terrible one. You may still be ahead (MP1 is betting a One card Flush draw or is bluffing) and if not you got 10 outs to boat or better (1T, 3K, 3 8s, 3 5s).
I call down the river since it is very unlikely that MP1 is betting anything other than a legitimate hand, since you raised the turn.

Edit: Corrected Out count ;-)