a lower ranking member of a household whose chief contribution is to the care of the household pets, most specifically cats. Coinage from concubine.
Though armed with a doctorate in Medieval Japanese literature, she was unable to find meaningful work, and became a catcubine, living rent-free with friends in exchange for caring for their cats when they were away.
When you are trying to stuff your nuts into a woman's fart pipe and as soon as you cram one in, the other nut pops out. Leaving you with only one nut in her asshole, but never two. - Very similar to trying to get two or more cats in a bathtub, one always escapes when trying to get the other in.
The only man to accomplish this feat is the very famous "aww nigga, nuts in the ass dick in da pussy" porn actor. Who overachieved the feat by keeping both nuts in a females asshole WHILE stuffing his giant dong in her vagina. Making us all feel inferior.
Man, I was trying to stuff my nutsack into Bertha's asshole, but all I got was cats in the bathtub