How to play nuts Vs. Freeroll

I find myself coming to this situation often.
Take this hand for example.
Im holding 5 /images/graemlins/diamond.gif6 /images/graemlins/diamond.gifA /images/graemlins/spade.gifK /images/graemlins/club.gif There are 4 limpers.
the board comes
2 /images/graemlins/heart.gif3 /images/graemlins/heart.gif4 /images/graemlins/club.gif
So im first to act, and of course i bet the pot.
Villan reraises. Everyone else folds. (Villan is tight and from the previous reads i have gathered from him, i am quite certain that he has 5/6 and a freeroll flush draw.

So do i just check call check call and hope no /images/graemlins/heart.gif comes? or do i fold? I mean, the only thing im drawing to is a split pot and it would cost me dearly if he spiked a heart on the turn and even more so on the river.

[RickyG]

The answer depends much on stacks and opponent. If you are sure he has the same straight plus a freeroll, then you are putting in your money with the worst hand, which is always bad. If the stacks are deep, then it is an easier fold.

[wickss]

If you know the villian well enough to be sure that he has the same straight, you should almost always fold. Putting money into the pot to split it or lose it usually has a -EV. You need to be getting 2 to 1 pot odds (I think) on the rest of your money for this to be a break even bet or better.