NL 25 6-max, flopped set vs big raise

[Marc Desjardins]

Party Poker No-Limit Hold'em, $ BB (6 max, 6 handed) FTR converter on zerodivide.cx

CO ($39.95)
Button ($17.43)
SB ($3.93)
BB ($23.75)
Hero ($47.75)
MP ($25.63)

BB is 16/4/4.5 after 101 hands
MP is 74/6/0.97 after 106 hands
CO is 35/7/1.11 after 103 hands

Preflop: Hero is UTG with 5[img]/images/graemlins/heart.gif[/img], 5[img]/images/graemlins/club.gif[/img]. SB posts a blind of $0.10.
Hero raises to $1, MP calls $1, CO raises to $1.75, 2 folds, BB calls $1.50, Hero calls $0.75, MP calls $0.75.

Maybe a bit agressive to raise here, but I do this all the time, often I can pick up the pot after the flop if nobody flops anything and if I flop a set, then I can make a lot of money. I think the call of the min-raise is standard here, especially with a cold-call in there.

Flop: ($7.10) 5[img]/images/graemlins/spade.gif[/img], 9[img]/images/graemlins/diamond.gif[/img], 6[img]/images/graemlins/heart.gif[/img] (4 players)

Perfect flop! I lead out because I was re-raised, so if he has a big pocket pair, I can make a lot of money. Is the bet amount good, do you bet pot? or maybe you even check and hope for the check-raise? At this level, I'd rather bet out, but what do you think?

BB checks, Hero bets $4, MP calls $4, CO raises to $15, BB folds, Hero...

OK, what should I do here, I can't be afraid of the straight and even if by some luck he has it, I have a lot of of redraw to a full house. But the thing is, do I want to keep MP in for the ride. Should I worry about the over set? I put CO on a big overpair, but I have no idea what MP could have, he could be drawing to a straight so I kinda want him out. I'm thinking re-raise, maybe even put it all-in and hope he can't get away from AA or KK, but I'm really not sure.