So even if I drink 3 gallons of water a day, it won't make a bit of difference?

So my only failproof option is substitution.

It's a matter of finding a means of getting the urine into the cup unnoticed.

It has to be possible. Gonna practice with the bottle, plastic wrap, rubber band, and water today. And if anyone has any other ideas, thank you in advance.

And thanks to those who posted here.

Edited after Knot's post: FOILLLLLL! Of course that would puncture easier! Okay, it seems like we're onto a plan. If you're saying they observed her and no one saw. I like the long shirt idea. I'll wear something really bulky. Maybe even a really tight girdle, as stupid as that sounds, so I have an excuse to be adjusting things down there. Alternatively, I could pretend to have to fool with pads or tampons..

I'm really glad it worked for your friend! Gives me hope I won't get caught!!