Villian seems like a TAGfish, 20/15/2 seems really spewy thus far. My image is not great at the table as I have had alot of good hands and have been active but have been getting drawn out on alot and have made a few difficult laydowns at the table.

Effective stacks are 120

Hero is UTG +1 with [X][X]

UTG folds, Hero raises to 3.5, folded around to villian in the BB who calls

Flop [4s][2d] pot is 7.5

Villain checks, hero checks

Turn pot is 7.5

Villain checks, hero bets 5, villian raises to 18.12, what hands would you call here with? what would you raise with and would you ever fold here?

Just thinking about the line the villian took, it seems like everytime I see it, it is uber bluffy, but maybe it is actually a good line to take against thinking players when you do have a hand.

I actually use this play myself sometimes against non-thinking villians sometimes when they bet a tiny amount on the turn.

I don't know I've never not CB that flop imo.

He is either bluffing (pretty poorly) or selling a bluff.

I doubt he is selling a bluff cause of what Ice says. If he is thinking then this is a very sophisticated play for him to be making and I think considering that you mentioned youve noticed villain is pretty spewy that this is a call if you have showdown value of any kind.