Those who have watched/read Full Metal Panic will understand this joke, those who haven't lemme explain.

First: Sousuke is an airhead. Lovable, but still an airhead none-the-less. In the very first episode of Full Metal Panic, Sousuke, along with his companions were getting him ready for his next undercover mission as a high school student...so they gave him all this stuff that normal high school teenagers have. And a condom was there, and this was what the conversation was KINDA like..

Sousuke: What's this?
Melissa- A condom.
Sousuke- I'm aware that it's a condom, but why would high school students need such a thing?"
Melissa- Hey, don't pretend to be so innocent, you dirty old man!
Sousuke: What are you talking about? I've used it before.
Melissa: Woah!
Sousuke: I was all alone in a jungle and lost everything...everything but this. You know it can hold a liter of water.

And for some odd reason that scene was in my head at work.....and this came to be while I was there. I don't know how, but it did. I had a different ending in mind..and it was so much better......but I forgot it by the time I got home. lol. Soo....ending is not ftw. But the condom on his head is kinda funny I suppose. I dunno....maybe I'll take another shot at it another day.