okay first i would try to act normal like his not a celebrity and if that doesnt work out which i know wont ill just be like wow ustin bieber and say i upendo your muziki and wewe and then take a pic and have him autograph it then ask to exchange digits
I would hug him and then say"Hey Justin,how are you?I am one of ur biggest fans,I upendo wewe very much,can I get an autograph?Do wewe wanna be friends?"
If I was to met Justin Bieber I would treat him like any other normal teen. What I mean is I wouldn't faint au scream au kiss him au faint some more. I would just talk to him and ask him some maswali like 'what's ur inayopendelewa color' n stuff so I could get to know him.