I seem to have to go less on the bike than in regular life. I do have to go about 20 times BEFORE a ride. Basically, our stops are at gas stations, port a potties, or other stores where you can use the bathroom without buying something. However, there have been times when I go behind a bush or here in New England, a stone wall. I am fast at it, too. But one time my friend, who always has to go, went to pee behind a public library where we were waiting out a rainstorm (another story). It was a Sunday, so the library was closed. Just as she got her shorts down, a car pulled into the lot to return a book and got a good view of her!
There are often port a potties at playgrounds during the prime riding season and at schools. We use these a lot and it doesn't bother me a bit.