Putting Julie and your belly onto the table, you reach below and pull Lizzy's tail into position. Lizzy objects, but only to you moving her. She then puts herself in what is the identical position as far as you can tell.

A hand goes on each lovely thigh and your vitals go in the middle. You hear Julie saying "Ooo, I know what you are doing.", but you are concentrating on your thrust into Lizzy, which is met by a happy gasp from under the table.
You start vigorously thrusting, which gets approval from below the table and above, tho Julie reports that, as is often the case, sex increases digestion and she is rapidly dissolving. Indeed, before you come, all you hear from your stomach is a gurgle.
It takes both of you some time to come, but you come nearly together. A great celebration of Lizzy's success. True, she needed your help, but her meal was still hostile.

About time for your next class. You gather up your stuff, and that of Lizzy's food, and head to class. This is shop.

You wonder at so many women at a shop class, and ask Lizzy. She explains that in many cases you don't want to eat a girl right away. So she is shacked until meal time. Thus there is a need for various shackles and restraints.

"All these ladies expect to take prisoners?"

"No, they expect to be taken prisoner."

"Huh?"

"If you are going to be in handcuffs all day, you want to be in a comfortable set, and what better way to assure that than to make them yourself and have them on hand for when somebody does grab you?"

"I suppose your cuffs have a way for you to escape."

"No. They have a way to get out of them if I need to. But that is not to escape. If I used them to escape, word would get out that I cheat, and then they would use restraints I can't get out of. And if you get caught once, you will be caught again.
"Now, I need to get to work on my cuffs. You should duplicate that key, and sign up for your first project."