After drinking almost a gallon of water each, you are now waiting outside the bathroom waiting to hear if Lee's plan worked.
"Hey... I think...yea, It's definitely working", Lee shouted through the door. "This is great, I was so worried but it's going back to normal."
"Well, hurry up in there", you shout back. "I'm going to explode if I don't get in there soon.
After a very long half minute you hear a toilet flush and the sink water running. A moment later Lee jumps out of the doorway with a huge grin on his face.
"I can't believe that worked", Lee almost yelled. "Looks like whatever happened before was only temporary but now I'm the same exact size I was before."
"That's great for you", you exclaim, "but if you don't mind your blocking the doorway."
"Oh, my bad", Lee said as he sidestepped out of your way. "Good luck tonight, I'm going to stop by and see Jenn. This is going to be a great night after all. See you later buddy."
And with that he was out the door and gone. Any minute now Sarah is going to come over and in a few seconds you were going to be returned to your former glory. You were so excited your cock swelled to it's full 4 inches. It felt so good to finally get some relief that you closed your eyes. And within a moment or two you started to get some familiar feelings. You opened your eyes and looked down at your rock hard cock and for a brief moment you smiled. It was short lived however, as you looked on with anticipation it didn't seem to be growing at all. No, it was shrinking... again. How could this be happening, you thought. It worked for Lee but you were dwindling away by the second. Before long you were down to 3 inches, then 2, then 1. As small as it was before you gained a few inches back in your second trip to that damned bathroom.
You tried desperately to wrap your head around what was happening. Sarah would be there soon and you were as small as before. Now she will definitely not believe you and there's nothing you can do. You take a deep breath and try and gather your thoughts.
You begin to talk out-loud to try and understand what has happened. "Ok, Lee got smaller and then he reversed it just a few minutes ago. He said he went back to exactly the size he was before. Alright, so what did I do differently...? I used it twice...and...oh!" A sudden realization strikes you. "If I would have left without using that urinal, I could have grown now exactly like Lee did. But instead, it returned to the size it was before I gained back the 3 inches. I canceled out my previous growth!"
Just then, the doorbell rings...