I don't mean to sound rude, but don't ask for something like that. If he wanted 粉丝 to have his number, then they would have it. 名人 have their own lives and things to do, and if their 粉丝 all had their number they would never be able to get anything done. It's honestly disrespectful to Jack directly, if 你 were a real 粉丝 你 wouldn't go around asking for his number. It's his own private information and its not to be shared. Again, no offence intended, I'm just saying.