I think that the odds of the above scenario are remote--so remote that I still don't see any problem with a teacher (college level) sleeping with a student who is not his/her student.
In any case, I 100% agree with your second paragraph, particularly the oft heard argument 'well, if he cheats as this, he can't be trusted with anything else.' People are morally complex. Someone may well cheat on his wife but abhor the idea of cheating on taxes, or always treat his customers fairly, or treat other people kindly, etc. etc.
Freakazoid = Matt Harpring. Just ask him - he won't deny it.
My Dream Draft '13: Trey 'Black Jesus' Burke & Glen Robinson III
My "back to reality" Draft '13 Dennis Schroeder aka "German General" & Giannis Adetokunbo aka "Greek Freak"