Ever wonder how cyclist pee on the saddle when placing and time are matters to them when riding in competition, but for MTB we have our own way to answer the Nature when there are plenty of bushes while we ride offroad. Those tips are taken from blog http://gzcycle.com an expatriate cycling club base in Guangzhou.
How to pee while on the saddle
Rule 1: Make sure you're safe from legal repercussions.
Urinating in public may violate indecent exposure, public nuisance, and disorderly conduct laws. In some places, you can become a sex offender for urinating in public. You don't want to have to knock on your neighbors' doors and notify them of your status. It's awkward.
Rule 2: Make sure you're riding on a slight decline.
If you’re going too fast, you don't want to lose control of your bike. If you’re going too slow, you don’t want to have to pedal midstream. You might as well just stop and get off your bike.
Rule 3: Learn the proper technique.
Extend one leg and rotate the opposite hip towards the extended leg. Free your member from the top or bottom of the shorts, and let it flow. Tap as necessary.
Rule 4: Make sure you really need to go.
The first time you try this, understand that Nature doesn't just have to be making a polite house call, ding-dong. Nature needs to be banging on the door with an oak cudgel, shouting and threatening to breaks windows.
Rule 5: Account for shrinkage.
You may not have as much capacity for extension as when you started the ride.
Rule 6: Once you start, don't stop until you're done.
It doesn't matter if you think you see the lights of an approaching car or an oncoming cyclist. Stay committed. Otherwise, you'll finish your ride with a soggy bottom.
And if you're a Woman... I have neither information nor advice for you. I'm sorry.