take needle nose pliers and bend one of the blades so that it sticks out a little bit at one point, when she tries to shave her cunt or legs it'll slice out a thin strip of skin. It'll freak her out and she'll never use your razor again, remember to throw away the razor and to not use it after you bend the blade.
my sister was using my razor so i dulled it up with rocks and used a pocket knife to slit the blade, surely enough the next time she took a shower she came out with a thin cluster of cuts on her leg.
