Matilda to the rescue?

"Wait Tammy! Stop!" Matilda screams to your surprise. Has she realized this has gone far enough?

"Can I do this please?" she says "I might be able to make it my science project for this year!"

"Oooo great idea" Tammy hands over the remote "I'm just gonna sit back and enjoy the show"

Matilda takes out her phone, pointing it at your naked (except for the hood) body.

"Matilda McKenzie. Science Project submission. Experiment one. We have a test subject strapped to the apparatus and using the Milk O Tron Mark 1, we will see how long it takes the test subject to ejaculate."

As the words leave her mouth you rock your head back in fear of what the machine can do, but relieved that no-one will recognize you.

"In 5... 4... 3... 2... 1..." Matilda counts down as the machine starts to slide at a medium pace up and down your tiny shaft.

You relax slightly and are thinking back to seeing Tammy's Transformers panties. As you do you realize that is bringing you quickly to the point of orgasm. Not only will the McKenzie sisters know how tiny you are, but also how quick you ejaculate.

It is too late for you now, you are past the point of no return. You stifle a moan as the first arc of cum shoots out for fear that your voice will be recognized. Another five strong arcs follow, before you hear Matilda:

"36 seconds. That concludes our first experiment"

"Well Sam, you don't last long, but you sure cum a lot" says Matilda as she removes your hood

You glance over to see a red faced Tammy biting her bottom lip.

"Please Matilda, can you let me out of this thing?"

Matilda looks over to Tammy who nods.

"I gotta go input this data and make sure the video recorded ok. I'll leave you two lovebirds alone" says Matilda as she throws the remote to Tammy before leaving the garage.