They scissor.

Ruby broke the kiss, smiling at Yang. "That was great, sis..."

"Thank you Mistress, I live to please you..." Yang moaned, continuing to caress Ruby's rear end, and pressing her chest into Ruby's hands. Her gaze was full of adoration for Ruby, both as her sister and as her owner. Yang could barely believe how much she loved being a ****. Though, **** probably wasn't even the right word. After all, the full definition included it being against the enslaved person's will, which was not the case here in the least, so servant was probably more accurate... But the term **** was just so hot to use, so Yang ignored the technicality.

Ruby then placed her hand on Yang's shoulders, and brought them both down to be seated on the floor. She then scooted her hips closer to Yang's placing one leg over one of her sister's, and nudged Yang's other thigh with her other foot. Getting the message, Yang immediately lifted the leg, letting her Mistress get her foot under it.

Both of them did a little more scooting, and pressed their vulvas against each other. "Oh!" Yang crooned at the sensation, and wasted no time grinding her hips to rub their kissing nether lips together.

"Unh..." Ruby moaned at this, returning the motions as she leaned back, supporting herself with her hands on the floor. Yang mimicked the posture, adding an arch to her back as she did, allowing her impressive assets to be on full display.

They bucked and ground their hips together for several minutes like this. Side to side, up and down, Yang made sure to perfectly mirror Ruby's motions for maximum mutual stimulation. Eventually, Ruby leaned forward, grabbing Yang's shoulders to pull their upper bodies closer. Yang didn't even hesitate to cooperate with the motion, allowing her breasts to press up against Ruby's, and they added rubbing their chests together for the stimulation.

"Oh, you've got all the luck, sis..." Ruby moaned, feeling a bit envious of Yang's chest. "...say, could you...?"

"I'd gladly make your boobs as big as mine if you asked Mistress, but I think that would detract from your own appearance," Yang murmured in an elated tone as they continued to grind their intimate bits against one another. "Maybe a slight enhancement, but your frame suits your perky little tits... Bigger is good, but it doesn't automatically mean better..."

Accepting this, Ruby leaned in to kiss Yang again, which Yang happily returned. They picked up frantic speed in their tribbing, even as their hands explored each other's bodies. Picking up the tempo as their hands stroked each other's sides and backs, they also deepened the kissing, and Ruby luxuriated in the feel of Yang's pillowy bust pressed against her.

Their labias began to twitch and spasm from all the stimulation, and they both gave muffled cries into each other's mouths as they reached the apex of pleasure together, their bodies spasming as their climaxes pulsed throughout them. "Unh," Ruby moaned as Yang leaned back, letting Ruby lean forward until they laid together on the floor, Ruby atop her sister and ****, continuing to make out with her. Yang's legs dissolved back into the violet mist and recombined into the tail, reattaching to the spout as they lost themselves in the intimacy.