Is she allowed?

Convince the twin in white to serve you first

You look at the twin in white mischievously. All of the power of the book doesn't mean you can't try to take some on your own. You ask her, "You really care about your sister don't you?"

"Of course I do," she replies, "but she's not that good at getting permission. The whole outfit makes her too embarrassed, so she ends up like this." The girl in the white bikini gestures to her twin sister in black. The girl's face is a stuck on a dumb expression. She doesn't seem to follow the conversation with her eyes.

The twin in white's gesture pulls at the other girl's bikini simply compounding the problem she's trying to solve. "Can she have your permission?"

You smile at her, "Honestly I think I like you better." You laugh lightly while the twin in white frowns. Continuing you say, "I have an idea. If you take care of one sexual act for me, then I'll take care of your sister. You can do it right here."

She looks startled and sputters, "That's not really what I was asking for. I came two days ago and I'm fine." She looked awkwardly around the room wondering if anybody had taken notice.

"That would be more embarrassing than that outfit," you begins, "if you got down on your knees right now and gave me a good blow job. Your sister is almost too dumb at this point to feel sensations, so it would take a lot of my time to help her. I bet you could make it worth it to me?"

She stares at you with a mix of horror and shame. The options puzzle around in her head.