Guy in my class gave me his Snapchat screen name instead of his number?

I'm 20 & met a guy in my class 2 weeks ago and long story short, he is definitely crushing on me. When class was ending today, he gave me his username to add him on Snapchat (a photo messaging app for iPhone). He said I should do it because I "won't regret it" and his pictures of him making faces will "brighten my day". He didn't give me his phone number or facebook.

I've never had a guy give me his username instead of a phone number before so I'm kind of over analyzing it:-/

On a side note, I didn't know what Snapchat was so I googled it and it seems like a lot of people use it for sexting and sending nude pictures so I hope those aren't his intentions.

Does it mean anything if I got his screen name instead of his phone number?

He could just be nervous and doesn't want to ruin things by having an awkward conversations and feels as though he could win you over with fun faces. It's not used just for sexting even though I'm sure a lot of people do. I'd see how it went. It really could go either way. If he tries getting provactive tell him straight up that's not what you want. If you want his number just be casual like at the end of class just say "Text me later" which will envoke the "I don't have your number, what is it?" I've done it before and it's worked for me.

It may be less pressure for him to do that, since there's a lot of pressure behind phone numbers as they typically mean the person is interested in you romantically. This could be a first step to asking you out, much like adding someone on fb.
I would see what he sends, if they are innocent pics, then that is probably the case. However, if they are dirty or he asks you to send dirty ones, then you have your answer!