He will def stare like crazy.Might get sweaty and nervous around you.He might even get a boner from looking at you.This is what my bf did to me before he asked me out(:
What Are Some Signs A Boy Likes A Girl Without Talking To Her?
He looks your way and you can feel it and when you look, you catch him looking away or looking down.
He will smile an look at you when he thinks your not looking. Plus he will also be checking out how you deal with issues when you think he not paying attention