Only what all of the other girls do with him

"I think it's finally time for you to give to me what you've been denying me. We can do anything, hm? I wonder, what might a gentleman like yourself and a woman like myself occupy ourselves with behind closed doors," Beelzebub murmured in a sly, seductive voice, taking his tie in one hand and running her gloved hand up its length until she reached the knot.

"Chess?" he questioned, raising an eyebrow.

"... Is that your idea of a joke?" she questioned, responding by raising her own. She lowered it again, looking unamused. "Try again."

"... If you're suggesting I get up to anything with the other girls, you should know, we're just dating. I'm not at that level with-"

"Taker, please. I've seen your laundry. I've seen all the girls' laundry. I know that you two are getting up to some not-so private private affairs. You're probably doing it outside of the house much of the time, or somewhere especially crafty, but the stains on the bedsheets and clothing can't lie. You've been having sex, and a lot of it," she growled, no longer beating around the bushes. "And I want to know why I'm not getting a piece of the action."

The Helltaker frowned, looking sideways and adjusting his tie uncomfortably. He clearly didn't want to bring his private activities with each of the girls out into the open-- this whole thing only worked because each of the girls tended to turn a blind eye to what he did with the others. "I, uh... That's not really proof. I don't think you've got any real hard evidence that I do anything like that," he countered. "So that doesn't fall under the umbrella of things we can jump into." Truth be told, he just knew that Lucifer was going to kill him if she found out he'd fooled around with her mortal enemy, Beelzebub, two days after bringing her out of the prison. He had a collar that could stop Beelzebub from that side of the equation, but he had no such checkmate over Lucifer.

"Well, then we will choose one of your little exploits I do have concrete proof of. Will that satisfy you?"

"Name it," the Taker answered, although he was already fearing what kind of pictures she might have snuck when he wasn't paying attention.

"... You let it slip just a bit ago. You've had experience watching Zdrada use this collar before. Furthermore, that little bit the Bitch Demon said to Lucifer when we were listening through the portal doubly confirms it! You've had experience using this collar in some sexual manner with her, haven't you? Let's do that," she finished, pressing one finger up beneath his chin and tilting his jaw up while a smug grin spread across her face. "Whatever it is, I want in."

She saw the man's throat shift with an inaudible gulp. "You sure? We can do something more normal like-"

"No! Exactly the same way. I want you to do it exactly the same way with me~" she chuckled, moving her hand from beneath his chin to caress the side of his cheek. She gently lowered his head so that his eyes would lock with hers. "Every detail, exactly the same. No more treating me like some kind of unwanted outsider. Show me how you really treat your girls."

"The way I treat Zdrada is, uh, a little different than the way I'd picture myself treating you-"

"No getting out of it. Exactly the same way," she reiterated, now grabbing his head on both sides to keep their eyes locked. "It's only fair."

"... Right. Just remember: you asked for it."