As a former middle school teacher, I can tell you that I witnessed plenty of young boys wearing the bracelets and laughing about it with their friends. Some were just not mature enough to wear them for awareness but were instead wearing them to get a good laugh out of their friends using the funny word.
Next to my classroom was a veteran teacher who had a long struggle with breast cancer and a masectomy about ten years ago. She told me she was offended by the bracelets since they did not do anything but raise awareness for the debate of whether or not they should be allowed. She said the bracelets took away from the seriousness of the cause to try to raise money for a disease that was often deadly. Our district did 'ban' them for that reason, but allowed students to wear them inside out and they couldn't call attention to the saying inside.
Our instructions were to give the students the opportunity to turn them inside out. If they didn't comply, we were not to argue but to send them to the principal to once again ask for compliance. We weren't taking away their right to wear them, but we wanted them to be respectful of a very serious cause.