Congrats on your first long rides. I'm addicted to my 35 mile route! I need to find a similar ride here in Atlanta so I can do it more often.

I have the same problem, and just bought a really small, lightweight lock for tinkle-breaks when I'm alone. It's just enough to deter someone from just riding off with my bike. My DH is usually with me to watch my bike when I need a break, but he's not around for my local rides. Holding it is not a very healthy option - it might cause you not to drink as much as you should, and it could cause a urinary tract infection (I suffer terribly from them) so try to go when you need to.

I still wanna know what the boys on the Tour do when they have to go!