Dating Guy Who Blows Up My Phone Until I Answer!

Buzz Question - So after 2 dates , this guy is blowing my cell up. I told him I would get back to him but he's the TYPE to keep calling your cell phone if you don't answer. Like literally 11 calls.. He's a great guy, but he has this thing where if you don't answer him he BUGS the hell out of you until you do.  Is this a RED FLAG?