Nice play.
White played some horrible moves there, Nh4 and f4 look hopeless and 21 ... fxe5 looked like his last chance to save anything. It was all over long before he went near that pawn, probably grabbed it as a last desperate bid for some kind of counterplay, far too late.
But I liked how you held the position in front of his King. Good stuff.
Sometimes it is better to not take pawns.
Here is an example. My oponent made a few mistakes before the infected pawn was taken by the queen. But i think it is a good example when not to take that certain unprotected pawn.