Ok so I really like this guy (obviously) and he seems to like me back. We say hi to each other in the hall and talk occasionally (I typically start the convos). Today I say him talking with somebody during passing period while I was walking. We both made eye contact, he smiled, said hey and waved and then I said hi. I'm pretty sure he likes me, my friend told me that in the library he was totally staring at me the whole time and didn't sit next to who he usually sits with. The thing is that he's super popular, so I don't know if that makes a difference. I would say I'm middle of the road popular wise. I also see him up at the gym. So I want to ask him for his number. How should I go about doing that? And what should I do once I get his number?