If you don't know already, the condom challenge is when you snort a condom up your nose and pull it out of your mouth. Ewwwwwww.
Here's a quick GIF guide to this disgusting, horrible thing that no one should ever do.
Source: twitpic.com
Teenagers are doing it and then posting it to YouTube for some reason.
Source: youtube.com
Teenage girls are doing it.
Source: youtube.com
Teenage boys are doing it.
Source: youtube.com