how weird is it to contact someone that you fancy when you haven't given each other your numbers or anything?

basically i fancy this guy that i got off with and after much deliberation i asked our mutual friend for his number tonight but she'd have to ask someone else for it. so i'm not too keen on that. i'm also not too keen on sending the creepy facebook message. a couple of my other friends said that i should just add the guy on facebook and get it overwith, but i think that would be a bit weird as well.

on the other hand i would really like to see him again, in a casual setting like (not like go to the pub just the two of us and make it awkward as fuck) and so my choices seem to be 1) get my friend to ask someone else for his number 2) do a creepy facebook message/add thing 3) wait until i run into him which could be months from now or this weekend or anything in between, and i'd rather it was sooner than later.

inb4 don't ask the internet for advice.

thanks.