Lillian, asking Gary to take her anally like Peter

"Well, I'm a little ashamed to admit it..." Gary said, blushing a little. It was so ridiculous to be blushing like this when he and his girlfriend's mother had just enjoyed their own orgasms together, but he was embarrassed nonetheless.

"It's alright, Gary. Here at the Bernstein home we don't judge anyone, no matter who their partners are or what their interests lie in. So please, go ahead and tell me who it was." Joyce was staring intently at Gary, still naked, still covered in sweat.

"Well," Gary said. "It was my sister, Lillian."

There had been a knock at Gary's door that night.

"Can I come in?" Lillian had said.

"Yeah, sure," Gary said, hiding his phone under the covers. No need to let his sister know what sort of things he was watching in bed.

Lil crept in the door, shutting it tight behind her. "I want to say sorry," she said. "I knew you were hanging out with Peter today, but... I didn't know the two of you were, you know... like that."

Gary was mortified. He knew that someone must have figured out what he and his friend were doing this afternoon, but he had hoped that he wouldn't have to confront it himself. He should have known better, apparently.

Lil sat down in the desk chair, not quite meeting her brother's eye. "Does Bernie know?" she asked.

"No," Gary said. "I haven't told her."

"Oh," Lil said. "You really should."

"I know," Gary said.

Gary and Lil had been close for years, ever since they had grown out of their silly competitive I-hate-my-sibling phase. But this was always a sphere that had been strange to touch upon, no matter how unorthodox the Menard family was in its openness.

"You guys looked like you were having fun," Lil said.

Gary blushed. He didn't know that Lil had seen them together for more than a second or two. "We were," he said. "Were you watching?"

"Yes," Lil admitted. "I'm sorry."

"It's okay," Gary said, hiding his erection under the covers of the bed.

"I was wondering," Lil said.

Oh God, Gary thought. I really don't want to have this sort of conversation with my little sister. "Yeah, sure. What's up, Lil?"

His sister looked away again, clearly not quite ready to ask her question. But it must have been important to her, so she mustered up the courage and opened her mouth to ask. "Could you... could you fuck me like that? My boyfriend doesn't want to touch my butt in that way."

... Lil and I decided that we couldn't do it in the house. We didn't want Mum or Dad catching us. So we decided we'd do it in the forest, in Stuart's van. Do you think that's okay?"

"Yes," Joyce said, smiling and nodding. "But I'll repeat my invitation. If you and your sister need a place to be sexual together, you can certainly come here. Naomi, um, Bernie, is OK for you to be sexual with your sister if you include her, as she said, and as she and I are sexual together, I can hardly have any objections. So how did things work around to that day in the van?"