2/4 pair plus FD on flop

[Roswell]

2/4 NL on UB, all stacks about $400. MP1 and button limp, SB completes, I check BB with 6 [img]/images/graemlins/club.gif[/img]4 [img]/images/graemlins/club.gif[/img]. Flop is

8 [img]/images/graemlins/club.gif[/img] 6 [img]/images/graemlins/spade.gif[/img] K [img]/images/graemlins/club.gif[/img]

SB checks, I check because I don't like being out of position with this hand. MP1 checks, button bets pot $16, SB min-check raises to $32. I think above whether to reraise but decide I have no fold equity. But I think the stacks are deep enough for me to just call, so I do. Then MP1 raises it to $125. Button folds, SB folds, back on me.
I know MP1 to be a very nitty player.

Thoughts about my flop play? What should I do now?

[Annorax]

Fold... I'm seeing bottom two or bottom set here, possibly another baby flush draw that's probably bigger than yours. Possibly even just Kx, but even that's a favorite over your draw.