You should block their hand next time using paint.

I'd be betting the turn when they check, don't see them checking any two pairs or sets here, only hands I see are fds and air. River is a bit meh, there's a 4 straight on the board.

I don't hate either calling or folding, I want to say I'd call because draws missed and their turn bet looks very suspect, but I think because I see their hand it makes it a bit bais.

I agree with betting the turn for value once he checks.That also makes it more likely he will check to you on the river protecting yourself from getting bluffed. He might take this line with AQ or a bare Ah so there's plenty of value there.

As played it's now a sticky spot but I don't actually mind a call because of how little he should have 8x and he can bluff quite wide once the four straight comes.