[patrick10]

the problem is the way it was played you have very little idea what villain has.

He could easily have many kings here but also draws + PP you have beat.

There is another thread titled "set played too agressive? " or something like that which is somewhat similar to this, in that you are dealing with a villain donk betting super weak into you.

I tend to disagree with you and think that you should raise the flop. Bump it up to $6- $7 and then you have an easy C/F decision on later streets- as played, you put ~$9.5 into the pot after the flop and still didnt know where you were at ...