An ex-girlfriend or ex-boyfriend is someone who was previously in a romantic relationship with you but is no longer your current partner. The prefix "ex-" signifies that the relationship has ended or terminated, and both individuals have decided to go their separate ways.
People can become exes for various reasons, such as growing apart, differences in values or goals, conflicts that couldn't be resolved, or simply realizing that the relationship wasn't working out. It's a common term used to refer to a person with whom you were once romantically involved but are no longer together.
After a breakup, some people might choose to remain friends with their exes, while others may prefer to cut off contact completely. The dynamics of post-breakup relationships vary greatly depending on the individuals involved and the circumstances surrounding the breakup.