As a grad student
Met a girl in a bar during grad school. We go out on a spectacularly good first date which ends up as a walk along the river by the building I go to classes in. I ask if she wants to see the grad office (room of desks), which she does.

I wasn't expecting much, but she sits on my desk, facing me with her legs open and almost around me. Things are heating up when the janitor opens the door, sees us in the dark and says, "excuse me" and leaves immediately.

She is embarassed, so I talk her into visiting the computer room inside the office space, which locks. The door can be barricaded, and there's a couch. Despite the interruption, we end up in various stages of undress. Both half nude, I am over her and ask about the other guy she is seeing.

"How, uh, serious are you"?
"Not this serious," she replied.

It was a good night. . .

But on Monday, I pull said janitor aside and thank him for his discretion.

"Oh, that was you"? he replied. "Don't worry. I've seen that in every building on campus."

But he declined to talk any further on it, a discreet and accidental voyeur. Judging by that comment and his silence following, he probably could've blackmailed a lot fo people.
(ChiTown Guy Dating when 35+: sane, single, attractive - pick 2, Sun 14 Oct 2007, 8:05, Reply)