"How do I know that I won't end up as your slave?" you ask. "How do I know that you're not evil, and trying to trick me?"
"You don't", your mom replies. "But you've known me all your life".
"And I'll be able to control my size?" you ask.
"Yes", your mom says with a smile.
"I don't want to be some strangers slave", you say. "Even if she would be nice to me. It's weird but, I don't really mind the idea of being your...toy".
"That's because your not a normal human", your mom says. "I told you, my kind have a different morality. You're my son, and love you as my son. But at the same time, I can just as easily love using you for my sexual pleasure. So..does this mean you're...giving yourself to me?"
"I'll let you...use me", you reply. "But I won't be a slave".
"Of course not", your mom says. "But while I am using you, you'll have to do what I say. And you start right now".
You nod your head. And then you gasp in shock as you feel a tingling throughout your body.
"Don't worry", your mom says. "I'm just making it so you can change size at will".
Your mom had been sitting on the bath, like she was when she slipped you inside her. But you know that she hadn't stayed there. Because you know that you were inside her several hours and could tell whenever she moved. But now she stands up and carries you into her bedroom. Your mom is naked, like earlier. She carries you over to her bed and lies down on her back, propping herself up on her left elbow. She gently sets you down on her hairless pubic mound.
"Why don't you try changing size?" she says softly.
"How?" you ask. "And what size do you want me?"
"Just think about the size", your mom replies. "And I'll let you decide what size you'd like to be".
You pick a size and concentrate. At first, nothing happens. But after a couple of tries, you slowly grow to nine inches tall",
"Oooh", your mom says as she gives a mischevious smile whilst sexily licking her top lip. "That size'll be...satisfying".
For the first time since this morning, you feel somewhat embarassed by that.
"You'll have to get used to things I say when you're shrunk", your mom says. "When you're like that...I'm afraid you're just a toy to me. And I'm not going to pretend that I won't get a lot of enjoyment from using you. Now, be a good little toy and jump down between my thighs".
You turn around and jump of your mom's groin, landing with a slight bounce on the mattress, between her enormous, silky smooth thighs. You then turn around and stare down at the pussy in front of you. At nine inches tall, you pretty much tower above it. But even so, it's still a giant vagina. You still have some doubt about what you're doing. But it's fading, helped by you constantly tell yourself that, at least your mom is one of the most beautiful women around.
"Don't just look at it", your mom says breathlessly. "I'm getting hot. Get to work".
You slowly kneel down, and then you start: