Originally, the "original Dubbs" was looking for condoms, and didn't want "old dirty man" condoms. Without recourse, Dubbs decided to ask the RA. When the door was answered, the RA's wife was finishing dressing. The RA came, Dubbs asked "may i have a condom sir?" The RA gave him a queer look, and slammed the door.
It should be noted that Dubbs only initiated this task due to the promptings of Gracie-Poo.
Eventually, several drug companies used this coined term in marketing their birth control products and morning-after pills.
"Yo bro, I was banging my chic last night, and i was taking her anal virginity when a random chinese kid showed up."
"Ah shit, what a total dubbs mood killer."
"Yo man, I was so worried the other day, I thought I got my bitch pregnant... so I just gave her one of those new dubbs mood killers, and no more problem."