[moldman]

You beat QJ or a bluff. It's not a busted flush draw, so unless it's a missed gutshot draw, I doubt this is air. So, I'd fold the river.

I also check behind on turn if you don't want to commit yourself to pot. Then you can call smallish bet on river. If you're going to bet turn though, make it 50-55. Then you can't fold to BB river push.