C-betting flop HU

[Fadook]

I always c-bet the flop HU. But looking at my overly high Flop AF and how things turn out sometimes, I'm beginning to wonder if there are times when checking would be better. I'd like to put up a few flops for consideration, but before I do that I'd like to be sure that I'm not completely wrong. Say only the BB, who's a bit on the loose side without being terribly so, calls your pfr. Are there flops you wouldn't c-bet?