Mari.

Mari climbed up onto the dining table and stood over her brother-in-law with her skirt pulled up around her hips to expose her wet, bald pussy.

"I knew it. You prefer me, don't you?" she stated as she squatted over his erection.

"Oh no, onii-chan!" Yuika protested, upset she did not get chosen, as she watched her sister lower herself down onto his awaiting cock. "Baka!"

"It is so big!" Mari sighed as her pussy hungrily swallowed his shaft whole. She leaned forward, resting her hands on his knees, and began bouncing on his meat pole. Her skirt flapped like a fan as she accelerated the pistoning of his cock in her cunt -- the tip of his cock almost slipping out from between her pussy lips before she slammed loudly down on his loins.

Yuika played with her clit while she watched her older sister ride him with her huge tits swinging back and forth. "I want his cock too..."

Mari slammed down one last time before she leaned back to let his cock slip out and unselfishly let her younger sister take his cock into her mouth.

"Does it taste good?" Mari asked, breathing heavily during her much needed rest, watching her sibling suck and stroke Shouta's long, thick cock.

Yuika did not answer immediately but when she finally popped his cock from her mouth she giggled, "It's delicious." As gratitude to her older sister, she help insert his cock back into her sister's pussy.

Mari leaned forward and rested her hands on his knees again. "You can cum in my pussy as much as you want," she suggested, looking over her shoulder, as she raised her ass up before lowering it violently down on his loins.

Shouta groaned and clenched the sides of the table as Mari bounced and gyrated on his throbbing cock.

"Cum all you want in my pussy!" Mari cried as she started to climax.

"No!" Yuika screamed and pushed her sister back, causing his cock to slip out of her spasming cunt just before it spewed a geyser of cum all over Mari's thighs and belly.

Panting heavily, Mari was sated enough that she did not complain about what her sister had just done. "I was so close..." she sighed.

"Onii-chan's jizz is mine!" Yuika whined, grabbing his still hard slick cock to suck and stroked it in defiance as their brother-in-law blacked out again.

"Impressive," Dr. Sugimoto sighed slipping her hands down to her own wet crotch.