Dead sims becoming the partner of living widow

The dead spouses of my sims are automatically becoming their partners again after death. I choose to become a freeroaming ghost and a little while after that, get a pop-up telling me that the dead sim has become the partner of the one still living. They ar3 no longer in the household and I don't want the ghost hanging around, so I place their tombstone in my sim's inventory.

Packs: Seasons, Cats and Dogs, City Living, Island Living, Get To Work, Get Together, Get Famous, Exo Lifestyle.