The first time they spit up on a friend who doesn’t have children. I’m convinced this is why some of my friends are still childless. Really, I am so sorry.
The first time your newborn son pees in your face. Yes, it really does happen. I finally got wise and started covering him up with a wash cloth while changing his diaper.
The first time they have massive diaper failure. I call these poo-splosions. They typically occur when you are in a hurry, you have placed them in your favorite little outfit, or have somehow forgotten a change of clothes.
The First time they put something really gross in their mouth. Babies are like ninjas. They have stealth reflexes. They can grab and lick the bottom of a shoe faster than you can scream “NO!”
Experienced parents will laugh; others may run screaming after reading this list. You are invited to add your experiences in the comments. http://www.neatorama.com/neatobambino/2010/11/06/20-awful-firsts-you-have-to-look-forward-to-with-your-new-baby/
And if anyone spits on me, I'll spit back - no matter what age they are.
I've baby sat my neices and one had bad diarrhea once and it started to leak out a little, but I'm sure that's tame compared to a real explosion of the brown stuff.
I hope I get to experience all of these one day w/ my own eventual children.