What level is he on with the missed diamonds?
Fact that youre UTG makes JJJ a lot more likely too. When you say he bluffs in bad spots, does that mean he's the type that will try to get you to fold your UTG overpair range here when the FD bricks?
I'd like a call a lot more if this was CO vs BTN than UTG vs BTN. I'd fold here on the river.