[modnareno]

I think a 2/3rd pot cbet wins the pot over half the time. If you really think he's playing back at you then bet/call or bet/3betAI.

This is not a flop I would be check folding though, it is very unlikely to have helped him, so he will either be a) forced to play a huge pot with a medium pair b) bluff with a worse hand c) fold.

In the long run, cbetting ~$40ish will make him make a poor choice.