I agree, you have to believe in your read. If he pot-size then your read only has to be correct 1 time in 3 to break even. In this case you had a much more reliable read than that. If he raises AI you need to be correct more often. Mabe it is best to already have planned exactly how you will handle each line before you check to him. Otherwise you may outthink yourself. Most people would not slow-play a set here with the 2 diamonds on the board.