Boarding school lessons

My High School leavers book begins with about twenty pages of photos. A few pages in, there are pictures of my friends with their boyfriends; all but two of those have the words 'three and a half minutes without a break, yeassss!' written above or below, in various different breeds of handwriting and pen, with varying degrees of accurate spelling.

I stared at it for a while waiting for comprehension to kick in, before giving up and calling for help.

"Yeah, we used to time kisses, don't you remember?" Charlotte said, sounding more comfortable with the idea that there was any need for.
"No! How!?"
"We'd put our arms round their neck, carefully crossed so we could see our watch.. How could you forget? I practiced on you!"
"Well, it can't have been that memorable an experience, can it?"

But seriously, I think it's probably best that I forget it- the thought makes me cringe.