So, when a Reddit user asked teachers everywhere, "Who was the worst parent you've ever had to deal with?" educators who work with students (and unfortunately their parents too) were ready to gossip.
As a music teacher, I had a mother of a student who would crash choir rehearsal for our Christmas concert and try to "demonstrate" how she had learned to sing "O Holy Night," when she had been a student.
Not only was her pitch 3 cents short of a dollar, but it took the principal and custodian to escort her OUT of the rehearsal room. For their part, the students thought it was a "planned comedy." It, however, was not! - Back2Bach
Not the worst but definitely up there with the stupidest. Currently dealing with a parent who thought I that I taught their kid about Jihad. We had Holidays Around the World before our Winter Break.