For money

"For science of course, for the betterment of mankind, but honestly mostly for the money." he admits with an embarrassed shrug, "It's been a long and, above all, expensive road to complete the prototype you now inhabit. I need further funds to continue the project. Fortunately, I was able to secure a generous grant from certain farsighted individuals, providing I can prove the unit's safety and efficacy. I believe this study can do that, with your help."

All his is news to you. When you'd signed up you'd thought you'd be helping test dick pills or something. You'd never her agreed to become a femme-bot, so some old weirdo could get rich.

"No way," you protest, "You can't seriously expect me go through with this Frankenstein bullshit. Put me back in my body now!"

He gives you a long look, seeming to be seriously be considering your demand before answering...