[Harv72b]

You have to call the flop raise because MP1 could be semibluff raising with a flush draw/OESD + over(s), an underpair, AT...you name it.

You have to call the turn bet because you picked up a draw to the third nut flush.

Assuming that by "fish" you mean loose/passive, I like leading the river & folding to a raise a lot better than check/calling.