It's been a long time

Location: small classroom of about 15 students
Topic: conversation analysis
Mood: students just finished a rapid-surprise-quiz and are ignoring the professor out of spite.

Professor: "INTERCOURSE. There, now that is something I can say to get you all to wake up and pay attention!"

Class: "Ha ha..." (muffled, sarcastic laughter)

Me: (Sarcastic smile, raised eyebrows)

Smart-ass Student: "You're going to wake us up with INTERCOURSE?"

Class: "MWA Ha ha ha!" (real laughter followed by mock-disapproval expressions)

Me: (unexpected, LOUD burst of laughter, followed by inability to keep a straight face for ten minutes...)