What “Braff” means
Braff means to show off, brag or flex, usually about something you own or have done. Someone who braffs a lot is showing out for attention.
Examples
Him love braff wid him new phone
He loves showing off his new phone.
Stop braff!
Stop showing off!
How to use it
Casual slang, often said with a laugh or a roll of the eyes. Calling someone out for braffing is mild criticism.