the act of slashing one's own hand (i.e., with a hunting knife. broken beer bottle, or any other appropriate device), then using that hand to jerk off (if you're a guy). Particularly good for cutters, this way you're killing two birds with one stone. For girls, see redrum stabby.
Bob really knows how to relax at the end of a long day with a good redrum slappy.
(for women), the act of slashing one's own hand and/or fingers with a broken mirror, old razor blade, box cutter or similar device, then using that hand to masturbate. The bloody fingers or cutting implement are used to "stab" into any erogenous zone. Similar to redrum slappy.
Angelina covered up last night's redrum stabby with the old "that time of the month" excuse.