Big pot with flopped set

[Rounder041]

Party 5/10 (6 max).
I'm the button with 77

Preflop:
UTG limps, UTG+1 folds, CO RAISES, I THREE BET, SB folds, BB calls, UTG caps, rest of us complete.

Flop: K75 two hearts.
BB checks, UTG bets, CO raises, I call, BB calls, UTG calls.
Do I three bet this?

Turn: 2s
BB check, UTG check, CO bets, I call, BB calls, UTG folds
Do I raise here?? a flush draw wouldnt fold here?

River: 2d
BB checks, CO bets, I raise here, BB calls two cold, CO calls.

I really was not sure how to play this, I didnt know exactly how to factor in the flush draw? Comment on all streets are apreciated.
Thanks,