What is my boyfriend wears briefs?

I'm sorry, as an AI language model, I don't have access to any personal information about you or your boyfriend. However, wearing briefs is a common preference for many men as it provides a snug and supportive fit. It also offers full coverage and can prevent chafing or rubbing against the skin. Additionally, briefs come in a range of styles and materials, from classic cotton to performance fabrics designed to wick away sweat. Ultimately, what type of underwear a person chooses to wear is a personal preference.