What should I do if my ex has an ambiguous object after breaking up?

Now that the two people have separated, let's be thorough and wish each other well.

You also said it was just the predecessor, not the current one. Two people are separated, which means it is not appropriate. No matter what kind of person the other person meets, it has nothing to do with you. All you need to do is start over, find someone you like, find someone who likes you, and be happy together.