K.I.S.S. keep it stupid, simple. how about Box the box. and he's looking for a bigger phallic box to put in his lady friend's box know what I'm saying gentlemen?

If it's not a very long game, and the theme isn't serious at all, it probably won't matter anyways. So just don't worry about it.

It'd be better to have a game completely without those elements, than to feel forced into putting them out there. If you don't already have this stuff in mind and need other people's ideas to get going, then it is going to come off looking that way regardless of how you set things up.

If all else fails, just go with a cliché. Such a thing won't take away from your game if you already know what you intend to do to make this game fun, especially if you are confident in your ability to deliver humor as-well. (big ass skelly gave the best suggestion as of yet. To toss that advice aside so callously means you are clearly not ready for this endeavor)