There are online suppliers of diapers that will fit teenagers, just search on Google or another search engine.
Go to the shop at buy them.
There are a few possible reasons for this spreading through fields from medical to sexual. I don't know how far your knowledge on this particular situation extends so I will answer based solely on...
some teens may have bladder problems; which could be a problem and cause them to randomly urinate..
No. Answer:Yes, some do.