Hallmark Movie Syndrome

Single women who try to interfere in marital relationships because they think "they'll be right" for reporting that a spouse might be committing infidelity, with no evidence and acting with actual malice, for a multitude of (usually selfish) reasons instead of minding their own business.

Samantha, who has never been married, has Hallmark Movie Syndrome (HMS) because 1) she was convinced that Aubrey and Tim were cheating on their spouses and 2) acted on her own disinformation to spread rumors 3) they were actually pultonic best friends, but Samantha cannot fathom this because she has HMS.