When my mother's cousin was a college student, she went home to her parents wearing her boyfriend's pin. Her father asked what that pin meant. She said that it meant that they were in love and intended to get married. Her father said if she planned to get married now, he didn't need to pay for her college anymore. She returned the pin the next day. They became engaged after college and have been married for about 45 years now.
This probably has little to do with the thread, but I think it's an interesting story.
I would return the pin or the lavalier if the relationship ended.