Ex-Boyfriend- Noun, Adjective
The term, 'Ex-Boyfriend' may be used in several instances.
1. The 'Boy' In question has turned into a Man, and is now your 'Man-Friend'
2. The 'Boy' In question has decided not to persue the relationship anymore.
3. You have decided not to pursue a relationship with the 'Boy' anymore.
4 {Rare} Both You and the 'Boy' Mutually decided not to persue a relationship anymore.
-Cited from "Clipper_2's Incomplete Truths"