Way to walk?

i have two groups to walk home with, my male friends (really immature) and my girl friend and her 2 friends (dont really talk around them). one day wen i was walking with my girlfriend some guy ask me to come so he can ask me something, so i told ma girl and her friends to walk up and i'll catch up, and the guy ask me do i knoe a someone, and wen i was about to say "no he grabed my hat and started running, i ran after him and he just left. it was one of the most scariest things that ever happened to me, cuz i noe if i caught up he would of stabed me or somethin, i dint tell my girl cuz it would make me look weak. so i decided not to walk with her no more cuz i noe im gonna see tha guy again, but i dont want to walk with my guy friends cuz there imature and i hate walkin with them, what should i do? walk alone?