The full form of EXBF is Ex-Boyfriend 

a former boyfriend

In social relationships, an ex (plural is exes) is someone with whom a person was once associated, in a relationship or marriage. As a prefix, ex- can refer to a variety of different relationships; for example, one might refer to a music group’s ex-guitarist, or someone’s ex-friend.

When used alone, ex as a noun is assumed to refer to a former sexual or romantic partner, especially a former spouse.

Ex-Boyfriend (brand), an American clothing brand.

Boredwalk is a California-based indie brand featuring graphic T-shirts, hoodies, gifts, and accessories featuring clever dark humor and progressive politics. The product line features original designs by Matt Snow, a graduate of the Art Institute of Pittsburgh and creative partner Meredith Erin. Throughout the years the brand’s products have been seen on television and across social media worn by influential figures.

“Ex-Boyfriend” (song), by Lil Dicky, 2013

David Andrew Burd (born March 15, 1988), better known by his stage name Lil Dicky, is an American rapper, comedian and actor. He came to prominence with the release of the music video of his song “Ex-Boyfriend” in 2013, which became popular with more than one million views on YouTube in 24 hours. He released his debut album Professional Rapper in 2015.

In 2018, his song “Freaky Friday”, featuring Chris Brown, became a worldwide hit. He also gained attention for his 2019 music video “Earth”, which featured many singers and actors including Ariana Grande, Justin Bieber, Ed Sheeran, Shawn Mendes, Kevin Hart, Wiz Khalifa, Charlie Puth, Katy Perry, and Leonardo DiCaprio. The song was made to raise awareness about the environment, pollution, and climate change. Burd stated that a portion of the song’s proceeds are being donated to a variety of environmental charities

see also What does EXGF mean? What is the full form of EXGF?