Mulder and Scully have been separated since July 2008, and it didn't end well. Scully was tired of the relationship, which was no longer healthy. Mulder was always cooped up in his office and didn't go out much, he only gave Scully a few minutes when she needed him and she worked overtime at the hospital so she didn't have to go home. Mulder loved Scully like crazy and Scully loved Mulder with pure, tender love, but that day in July Scully decided to end the relationship