Mari, Yuika, and Shouta in the dining room.

Dr. Sugimoto had given Mrs. Osano several miniature spy cameras that she could hide in the various rooms of her three-bedroom apartment. She noted from the viewpoint, the camera was placed in the corner of the LDK -- open-plan area that combined the living room, kitchen, and dining room, which makes up the heart of a typical Japanese apartment. Seated at the dining table was Mari, Yuika, and Shouta having breakfast -- Mari wore a blue floral-print dress with black underwear underneath, Yuika wore her schoolgirl uniform with a white top, blue flap collar, pink ribbon held in place with a white clip, blue skirt, and thigh-high striped nylon stockings that expose her toes, and their brother-in-law only wore a white t-shirt and black athletic shorts.

"How was it?" Yuka asked after her brother-in-law drank the cup of tea made for him. "Did it taste good?"

Mari giggled. "I wonder if it will start kicking in?"

Shouta pushed his seat back and stared at the massive bulge in his shorts.

"Wow! Onēchan, it is so big!" Yuika gasped, staring at the bulge.

"That is great. I bought this online because I wanted to use it on my husband," Mari smiled as she stood up, walked around the table, and knelt on the other side of the chair from her sister. "But he rarely comes home. I am sorry but I tested it out on you."

"Onii-chan, I heard what you did with my sister," Yuika whispered, kneeling down next to Shouta's chair.

"Me too," Mari added. "You know you should not have sex with your younger sister."

"It makes me sad," Yuika pouted. "So, I am not letting you off the hook today!"

"You need to be punished!" Mari giggled.

Then Shouta slumped, appearing to have blacked out from the medication. Shoko watched the sisters strip the young man of his clothes, leaving with just his massive erection.

"Onii-chan, your body is amazing!" Yuika gasped as her sister stroked his thick shaft.

"As I thought, it is bigger than my husband's," Mari cooed, caressing his glans with her fingertips before she bent her head down to swallow his cock. Not wanting to be left out, Yuika sucked on her brother-in-law's ball sac.

Shoko was impressed with the young man's stamina, taking notes on her tablet, as she watched the two young women continue to suck him off. Eventually Mari popped his cock out of her mouth to let her sister have a turn. Yuika tried to take more of his cock into her mouth but gagged, spitting out his cock. Mari stroked his cock while the two women sucked on his balls.

Shouta let out a low moan and apparently Mari feeling his cock throb in her hands, she hurriedly engulfed the his cock again, bobbing her head up and down he let out a loud grunt. She wrapped her lips around her cockhead until he was finished, only to pop his cock out to show him the massive load of jizz oozing out of her mouth.

"Tastes so good," Mari purred.

"I want some, onii-chan!" Yuika whined.

Mari leaned over to kiss her sister to share his cum, not noticing that their brother-in-law blacked out again.

"I will suck you dry," Mari cooed after he woke up a short time later.

"You must be so embarrassed, onii-chan!" Yuika giggled as her sister started sucking on their brother-in-law's cock again.

Mari popped his cock out and gave it to her sister to suck on.

The girls each grabbed him by the arm to get him to stand, only to push him to lie down on the dining table.

"Well? Mine are bigger, right?" Mari asked after pulling down the top of her floral dress to free her massive tits.

"Hey!" Yuika objected, lifting up her uniform's blouse to expose her large breasts as well. "Bigger tits are not the best tits!"

"Who is it?" Mari asked. "Do you want to do it with my big tits?"

The two young women stood in front of their brother-in-law waiting for him to answer.