Play it off as normal kinkiness.

You realize you can play this smart. As far as she's concerned you're just a guy obsessed with big tits. Doing so doesn't change the fact you have a magic boob growing notebook.

You turn around after getting an idea. "Hey, tell you what, rub em on my back and say the magic words. They'll grow for sure."

Denise chuckles. "Will they now?"

You nod and take off your shirt, all while carefully hiding the notebook in front of you. "Not too much, though, I don't want to be trapped in here."

It doesn't take long before you feel Diane's soft breasts against you back, rubbing alluringly up and down. "Like this?"

"Yeah..." you say, grinning. You write her name and 'K Implants' next to it. She really seems like the type that implants would look really good on her.

She works tirelessly and her breasts swell against your back. She puts her hands on your hips to get a better hold of you, her erect nipples practically scratch against your skin like nails. The fullness and firmness amplifies the effect. Needless to say, something equally as hard rouses in your pants.

Diane seems oblivious to the change at first but her words surprise you. "You like my big titties don't you? Are you sure they'll get even bigger?"

You glance back, concerned, but then you consider the context of her words. Implants. She means she made them bigger herself on purpose. "Y-Yeah. I can practically hear them filling up."

Actually. You can. The sloshing of silicone in her chest is impossible to ignore. It fades in time, but you and only you hear them 'fill' in real time. IT confirms she can't detect the growth under normal circumstances. It's almost dissapointing.

"Y-You know... you might be on to something when you suggested sucking me off... You don't mind if I make you bust out of your shirt, do you?"

Diane laughs. "You're crazy. It's totally hot. Seriously. What would you do if I actually started growing?"

But she did.

"Uh... I probably wouldn't be able to keep it in my pants. That's for sure. You wanna go straight for... you know... I have some raincoats."

Diane considers it, pressing against you long and hard. "Nah."

She reaches around and slips her hand into the front of your pants. "I think I like making you squirm. Let's put it off for a bit. I'm warning you though... you bust a nut early and I'm calling this off. Nothing worse than a guy with no stamina."

"R-right."

The notebook is practically calling to you. You could make her even bigger, but then you risk losing control... choices... choices.