They were once women.

 Now they are cumbunnies. 

The were brought to the lab by master's assistants. And exposed to phase one of his reprogrammining protocol that made them dizzy and happy, made their bodies hot. It seemed so natural to remove their clothes until they were naked.

Then, a little sting as the needles slid into their bottoms. And phase two began.

The room darkened, porn began to play. They watched men and women fuck, their cunts growing wet, their nipples hard. The soundtrack of the porn, under the wet sounds of sex and moans, a sexy, female voice repeated, "I am a cumbunny. I like cock. I like balls. I lick cock. I lick balls. I love cum" over and over as the test subjects watched, began rubbing their own tits and pussies and each others as cocks on screen began to pump cum. They watched as women were cum on, cum in, watched as it flew and splashed.

Then it was time for phase three. Assistants put bunny ears on the test subjects' heads. They looked like cute costume ears, but they contained antennas and magnets that projected a wave through the test subjects' brains making them dumb, submissinve, and nonverbal, but also so hungry for cock.

Now they live in the bunny pen, where they are washed, fed, and fucked. They look through the bars of the pen hopefully for cock, greedily suck any men that stick their cocks into the pen, and while one sucks, others gather, licking and sucking her pussy, ass and tits.

Their former lives are blurry memories now. They are cumbunnies.