So, one of the girls was caught performing…and one of the boys was caught receiving, I guess…fellatio.
Which led me to wonder, what excuse do you use?
“We went to the movies and were checking for theatre lice.”
“I thought it was a carrot and wanted to make a salad.”
“I didn’t brush this morning.”
Or, for those who believe they can really brazen it out:
“Penis? What penis?”
What excuses can you suggest?
I thought sucking on it might make the swelling go down?
I felt a little weak, thought extra protiene might help 
He was bitten by a rattlesnake…isn’t this what you’re supposed to do for snake bites?
Hey! Do you mind? We’re having a private moment here…
Hahahahahaha! That one’ll be hard to beat, alice_in_wonderland.
Dammit now you ruined it! We were doing a science experiment. And now you’ve ruined it! We’re going to flunk the semeseter and it’s all your fault!
“Molecular biology always does this to me.”
“Hey, it’s better than the cafeteria food.”
“I lost my eraser and I was looking for it in his pants.”
“I was just practicing for my extra-credit assignment.” winkwink
“Yes, your lectures are that boring.”
“He promised to do my homework later.”
“We were studying! You know – cause and effect!”
“Do you have any idea how much gum is stuck underneath this desk? Good thing I was down here to clean it up for you. Yum!”
Look at the instructor and say “If you had a choice between listening to this lecture or having oral sex, which one would you have picked?”
Turn, flabbergasted, to the recipient, and say, “Are you sure this is the ONLY way to inflate your sneakers?”
If she does it right, he won’t have to beat it. 