This is one of the most anxiety-inducing dreams to have, particularly for people who are happily in a new relationship or content being single — but it's also one of the most commonly misread.
Reconciling with an ex you have unresolved feelings about
If the breakup genuinely feels unfinished — no clear closure, an ending that happened for practical rather than emotional reasons — this dream often reflects that lack of resolution rather than a desire to actually reunite.
Reconciling with an ex you're at peace with
More often, this version isn't about the person at all. Exes in dreams frequently represent a specific period of your life, or a version of yourself, associated with them — the dream may be about missing that period or that self, not the relationship.
Getting back together while in a new relationship
This is normal and doesn't indicate dissatisfaction with your current partner. It's more commonly linked to your brain processing old relationship patterns as it forms new ones, especially early in a relationship.