Crazy huge dude

Ok, my ex girlfriend is going out with this crazy-ingly huge muscled dude and he wants to kick my ass and I am puny and scared. So I need to know where and how I can get a knife that is small and how I can carry it around my body at all times as to use it in case of defense (and defense only!).

I'm seriously scared and hope you guys can tell me how I can do this?

>>24
      I actually have no idea if this actually works, I just read it in a book or something.  Doesn't sound completely farfetched.  And no I don't suggest actually doing it.