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?

Oh, and fucking use a phillips head not that flathead shit, you'd have to be a retard to use a flathead, unless you're strong enough to put that shit through flesh, then it would be the superior choice for when you twist it after it has entered and as it is leaving it will leave quite the fucked up internals, but you said you were puny so definitely stick with phillips.