I was in 9th grade.

My friend wrote "I have big tits" on a piece of paper he was going to hang on the back of the girl sitting in front of him. 

Then the substitute teacher came down our row, stopped, and bent over to help the girl in question with something.

My friend's eyes went WIDE as he looked at this ass in front of him and I whispered, "don't do it man".

"I have to do this."

The rest is history still discussed over tequila shots. Good times, man. Good times