Should I text him or not?

ok... well i like this guy and he has a gf they have been dating for awhile now... but when i do text him i say that i am a sister or i am a friend i am never me when i text him i just scared cause we come from 2 different worlds he's popular and i am not i am a band geek... he gave me his number (and no i didn't ask for it) so should i tex him?