Will the parents be having sex in front of the students? No, but the lesbians will be flaunting their “marriage” in front of the kids.
I’m sure the school recognizes that all have sinned and fall short, but allowing blatant sin to continue in unrepentant full display each day (homosexual relationships) in front of the children would be unacceptable.
I don’t know - it’s a tough one. Can’t pick and choose.