I'd be like "Sup Jesus, I think you're a pretty sick guy and I have nothing but respect for you, shame your father is a bit of a c*** though". And then, if I go to hell for all eternity for 18-70 years of neutrality, I could be like "told you so, he really is a massive prick" to my christian friends.
Oh, and I'd love to discuss theology and philosophy with the guy.
For those who think atheists would burn him at the stake, I'd guess they share my opinion and would burn his father, but not Jesus. None of my atheist friends dislike Jesus at all.