Take one donk's stack or go for two?

New to NL 200
Button is playing very off. I have him labeled as "piggy bank" as he is raising and calling with very marginal hands.
MP is X-loose. I don't (think I) want him in this pot really.

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

Hero ($354.79)
MP ($458.02)
CO ($736.70)
Button ($112)
SB ($56.70)
BB ($335.35)

Preflop: Hero is UTG with A /images/graemlins/spade.gif, K /images/graemlins/heart.gif. SB posts a blind of $1.
Hero raises to $10, MP calls $10, 1 fold, Button calls $10, 2 folds.

Flop: ($33) 8 /images/graemlins/spade.gif, 6 /images/graemlins/spade.gif, A /images/graemlins/heart.gif (3 players)
Hero bets $25, MP calls $25, Button raises to $50, Hero ...

What's my line? Button only has 50 left but if I bet that MP may call with draw. Do I care? Should I push hard to isolate?

[jjb108]

TPTK backdoor nut flush draw but OOP. Given reads, I'd like to isolate vs button but don't want to build pot OOP. If you pot it to put button in and isolate are you going to put 200BB on the line with TPTK? Because you have the A :s: I call. The button is irrelevant he'll be all in on the turn. Concentrate on MP. I would rather showdown TPTK in a smaller pot here. 1/2 pot non spade turn. 1/2 pot a spade turn as well with the draw.

right. I see what your saying. button is really irrelevant here, but so far it seems like my hand is better than MP's and if I just call he is getting great odds to suck out on me which would put me in tough situation if a spade or straight draw card comes.

I'm leaning towards re-raising to about 2/3 - full pot