So this HB8 and I used to talk before now and we stopped talking and I liked her. Today was Formal Day for Homecoming Week at school so I dressed like a sexy beast in a suit and I walked in this room to help her and these two other guys with a project. Before today, we haven't talked barely for like 3 months and when I walked in she waved really excitedly and said "Wow you dressed up!" Then she insisted we get a picture and her friend took the picture and we had our arms around each other's waists. I commented on it, helped them, and left. I don't have her number anymore because I got a new phone, so now I want to get it by asking for the picture. On Facebook, should I message her when she's offline as if I'm busy and I only had time to send it and leave, or should I wait until I see she is online and ask her there so she can reply? Or should I wait until tomorrow at school if I see her? I prefer Facebook because I don't want my anxiety to ruin this for the second time. What do I do?

in order of preferability

ask her in person say 'hey ive got a new phone, can you stick in your num, i must have lost your old one.' but make sure when you say you lost it make sure that your poker faced in that your not really that bothered if you get it or not. and then add, 'by the way can u facebook me that picture.'

or mesage her offline saying can i get hold of the pic the other day as i think i may have to photoshop your face before it goes online ' just make sure that its clear its a tease not a insult.