she's basically bi-polar, & when he doesn't tell you why, you get angry.. then when she does, your dumbass says some dumb shit to make it worse
why you being such a bitch? get off your rag
are yu on your rag, 'cause you been acting all bi'polar and shit
Evolved from "on the rag" meaning having one's period, to "rag" meaning a woman who is having her period, to "rag" just meaning any woman in general.
DISCLAIMER: Women tend to find this term a bit offensive. Calling a woman this may slightly decrease your chances of getting laid.
Girl: (smacks him, pours beer on him, and leaves)
girl 2: She's on the rag.