That's really what this boils down to...stupidity, or perhaps outright ignorance. First of all, ANYTHING put on a computer, posted on a Facebook or Instagram account, or e-mailed can be shared, knowingly or unknowingly.
If this woman wanted to live dangerously and keep these little sessions with her boyfriend in electronic format, why wouldn't she keep them in some protected directory? Why co-mingle them in with her Calculus 111 materials? Why take even the slightest chance that the two (or more) files could get mixed up?
And as my friends on the Chicks on the Right said on their radio program yesterday, "these files will not be deleted, as requested by the college. They will go viral!"
More people will sign up for classes she helps in.