My husband and I share a realm, and he had a companion, Mable, who he dismissed for another companion in a Hunt Forest realm. When we got back to our Forest Abeyance base, Mable was already there, and had started chopping down the trees I’d kept in the courtyard area of our house and loved very much. We closed all the doors and locked her out, but then she started chopping the walls of our house with an axe at the point closest to the courtyard trees, clearly hell-bent on exacting revenge for my husband’s betrayal. There was nothing we could do make her go away until he finally created a new character, joined our realm, courted Mable to become that character’s companion, then left.
Moral of the story - sometimes a rebound relationship is what's called for.