Um...Is This Wrong?

Okay, I just got off the phone with my sister and she was telling me about a friend's hairdresser's boyfriend's son. (I'll pause for a minute so you may process).

Got it? Well, this woman, the hairdresser, her boyfriend's son is 16 and wears diapers. Now, understand, he is a "normal" kid. No developmental disorders which render his sphincter incapable of contracting (I love the word sphincter), he just never learned to "hold it". Is that not unbelievable? Is that not wrong? I'm flabbergasted. I just think that someone who can think and talk to other people, take high school classes like his peers, walk and chew gum at the same time, would not poo his pants. Apparently, the hairdresser went to do the laundry and walked into her boyfriend's son's room to gather some clothes and picked up some of his panties and was confused as to why they were so heavy. She was also dismayed at the smell. She asked her boyfriend about it and he told her it was none of her business.

Ok, here is me in this situation:
Boyfriend: Hey, if my son poos his pants, that is none of your damn business. If you love me, you love my son, no matter what he smells like.

Me: "Oh, ok. Later!" (And then I run out the door, grabbing only my purse, ID, and car keys, leaving anything else behind figuring it can be replaced.)

Is that wrong?