Did they go back to their ex?
If someone swore to you that they were over their ex,
then one day decided to go back to that ex...
LET THEM GO.
They are either:
1. A big liar
2. Indecisive about their feelings
Are either of those qualities really ones that you want in a partner?
You may be tempted to try to win them back,
or prove that you are the one for them.
But you are not the one for them.
You are the one for the person who doesn’t need convincing
and who is emotionally available and completely present in your relationship,
not partially claimed by some unresolved ghosts from the past.