i def dont mind betting this flop at all w/ backdoor NFD and 2 definitely live overs. problem is when he raises u if u call it sets up basically a reverse implied odds situation ... hes gonna bet everything except a Q or higher on the turn, and he will slow down the times u do make a pair.

so other options are b/3b the flop or fold ... between these, when u b/3b hes probably not folding any pair in the hole and your equity isnt particularly great. its not a bad time to do it so u can balance your range for the times u have big pairs though in this situation.

also the fact that hes playing 40/40 makes me think that he probably thinks u know hes playing too many hands and just flat out wont be able to fold anything cuz his perceived range is just far too wide. against a tighter thinking player i def like to balance my range and b/3b/fold the flop a bit more, but i just dont see this guy folding anything, i guess for that reason i fold in this particular hand.