The following is rated PG-13 due to subject matter.
I grew up with a weak stomach. I gag (or cough, as my children say) easily. I gag when I plunge the toilet and watch the what-nots float off the plunger. I gag when I do the dishes and remove soggy noodles from the drain. I gag when I throw away old Fruity Pebbles that have soaked up all the milk. I'm pretty pathetic, now that I think about it.
We once had a kitten that had terrible gas - we called her the Great Sardini. It farted one day and my sister, who was holding her, ran her over toward me. In the process of handing off the Great Sardini, the kitten's tail dipped into some tea next to my chair. So when the kitten got on my arm I thought it was peeing on me. The smell of the fart mixed with the suspected urine caused me to lose my cookies as I ran to the bathroom.
My second daughter has the same weak stomach. Weaker even, maybe. If someone cuts the cheese and she gets a good whiff, she will gag. Poor thing, she was born into the wrong home (my wife, and all).
Anyway, I find myself now covered in crap. Yes, I know, it's my son's crap. But it's not as if we're sharing an ice cream here. I'm covered in his caca. And you know the strange properties of this stuff. Crap creeps up the baby's back. It gets on everything. And because it's nearby, every free limb flails into it. I swear, turds have a greater gravitational pull than other masses of the same density. How that's possible, I don't know. It's the tornado-trailer park relationship on a smaller, less destructive scale.
I'm covered in crap, but I'm not gagging. That's as good a definition of parenthood as any I can think of. That's fatherhood. It's my job. No one else can do it for me. And I do it because I love him. Yes, you were right: I'm not gagging because it's my son's crap. If another child crapped on me, he'd be covered in vomit. No questions. It would be nothing personal, mind you. It would just make me throw up.