It depends on the relationship you have with a guy. If its a guy who you feel there is a mutual attraction with, it could means he likes you. Yes, he could just be pleased to see you, but most guys won't light up due to see just another girl.
he is really into you!
Your (lack of) punctuation makes your message hard to follow.
Given that, I'll see what I can do.
Based on my experience, I'd have to agree not reading anything into it.
Let me clarify that. My daughter has a friend who is a lesbian. I had this preconceived idea that all lesbians are 'bull dykes', but I really like this girl. Whenever I see her, I light up, and I believe she sees it.
I don't know whether this is any help...
Well after a long dark night it's nice to see the sun. Right now you're something of that nature to him. You make him feel good about himself, about life, about everything.