Train her

"Bonanza."

Lucy went into a trance.

"Lucy, acting like a dog makes you horny. You must act like a dog during foreplay in sex, or you can't orgasm. You love acting like a dog. You'll buy an anal plug with a dog tail, a rubber dog nose, costume dog ears, and get two bowls, one for water and one for food with your name on them. You'll even do tricks for dog treats. When you're fucked, you bark like a dog, and when you orgasm, you howl like a wolf. You can only orgasm if you're fucked doggie style with the anal plug in. When I wake you, you'll be very horny but realize you can't orgasm without the anal plug. You'll beg him to let you go get an anal plug and dog nose and ears and then let you come back and have me fuck you. You'll do anything I want to make that happen."

The hypnotist woke her.

Lucy sat up. "Look, I really need to get some stuff before you fuck me."

"I fuck you?"

"Oh, yeah," Lucy blushed. "I really need you to fuck me. I'm a bitch in heat!"

"OK, but if you're a bitch in heat, get some dog treats and keep the collar and leash on."

"Anything!"

Lucy put her dress back on and left.