I would most likely freeze and think its a dream and then i would give him a hug. Plus a Kiss on cheek if that would be ok. After he left i would scream my head off and call all of my Друзья and tell them what happened
I wouldn't scream because he's not an alien,he's a human being. Would I be excited? Absolutely! I would chill with him and get his number so we can keep in touch.
I would Kiss him on the cheek hug him invite him to обедающий, закусочной if he has no plans tell him to give me his number freak out and when he leves Kiss him again