Pretty easy call. If he has JJ, J3, J2, 33 or 22, it is a horrible tragedy and I will shed a tear for you.

Of course, if he has AJ/KJ/QJ/45, he has outs. Even against AJ, any turn card gives him even more outs to hit a running 2 pair and counterfeit you.

The fact that you are posting this thread means he either had a set or bigger two pair, AJ and hit running 5's, or 45 and hit his straight. So which is it?