How do think Henry will react when he finds out that his father (Neal) is alive?

Huhm... maybe Henry'll react pretty like when he found out about Emma. Try his best to pull his father back. He does seem concerned about Neal when Emma told him the faked story about him. But I believe Henry will win Neal back nonetheless.

I think he will be mad at Emma for about 3 seconds. And then he'll forgive her right away.

Because it's okay if the Saviour lies, but not the Evil Queen.

I know he's a kid and everything is black and white to him right now... But seriously?

What I WANT to happen... Is Henry to get angry at Emma. And come to see that she isn't perfect. And maybe that would lead him to understanding Regina a little bit more in the future.

i think he'll be mad at emma for lying to him and want nothing to do with her or neal for a while and will be going through very mixed emotions for a while on whether he would rather stay with regina or emma. i think maybe he'll go to david and mm for support. obvisouly he'll eventually forgive emma. just not right away i think.

I think Henry will be the one who will bring Emma and Neal back together! I think he'll be so happy to have a father.

Your theory sounds good.

And if she tells him the truth he may still be disappointed that he lied to her in the first place.

It's going to be impossible for Regina to use this to get Henry. She can't cross the Storybrooke boarder. Henry is going on the road with Emma and Rumple so Regina can't get to him. I imagine that Henry will be upset, angry, but also curious about the truth. Besides he can't go back to Regina because he's too far to get back. Plus when he sees that she's with Cora he definitely won't go back to her. Also I have to say I'm glad he's going on the road with Emma and Gold, I was so afraid Regina or Cora was going to kidnap him.