What is the reasoning behind people 'bragging' about how unruly their kids are?

My 'boss' walked in to day and asked me when I went on vacation.

He stated that I was going two days after his kids were leaving with his mom on their vacation...

He smiled and said he was getting a vacation away from his 12 and 4 year old. His four year old is daddy's girl and won't behave for the mother and the 12 year old was threatened with jail for skipping school, again! He made the 'jail' statement with a little smirk on his face, kind of like 'Oh, well...."

I told him it sounded like he had his hands full - he got ticked off and started to defend his kids. "They aren't too bad..."

Why talk about them and when someone agrees, get ticked off??