You still have doubts

"Ava, are you testing my loyalty again by offering me any chick I could possibly think of? What will happen should I wish to fuck some celebrity? Will you tear me to subatomic particles?"

She giggles heartily. "Of course not, honey. I just want you to have some fun. Tell me a name! Any celebrity! I can make her younger than she currently is, I can bring hot chicks from the dead. I can even bring fictional characters into existence. All I need is your wish. Don't worry too much."

You ponder for a moment. Like any guy, you have a list of names in your head that you'd love to get laid with. Yet, you are not convinced that Ava will be fine with you fucking anyone but her. So, instead of telling a name, you ask another question. "Can't you just change your appearance to match whatever hot babe I suggest?"

She sighs. "I can everything. How many times do I need to repeat this? You are tempting me to..." Ava interrupts herself with a smile "If you really want, sure. I prefer to have appearances I enjoy but for you, I can endure some other body."

Right in front of your eyes, Ava transforms into Emma Watson, A naked 18-year old version of Emma Watson to be precise.

"Why her?" you ask slightly surprised

"I promised to not read your thoughts, silly," You hear Emma's sexy voice as she replies, "Many guys want this girl, you know? So I made a guess. Damn, I had no tits so small... Well... ever. Anyway, wanna fuck, or should I transform into someone else?"