I sometimes fold this because just looking at it gives me a sick feeling. One thing I hate about it is that we're not that far ahead of even the dregs of his range. But I'd guess your equity is probably good enough to call (because he is sometimes bluffing/semibluffing, and sometimes has a worse pair or kicker), so call. And try not to kick yourself when you see king jack and feel like you should have seen it coming.