About everyone else but themselves it seems. They have no problem ratting out their brother or sister. They have no problem breaking your heart by telling you that your breath smells like coffee. And they really don't mind sharing all the family secrets with perfect strangers.
Take for instance when we went to a second hand office supply store - the kind with furniture not the kind with printers and paper. The only person there was the one sitting up front. So of course my 6 year old had to chat her up. He told her his age, the age of all the brothers that were with us. Told her that his 8 year old brother had cancer. Told her, "And the baby isn't even a year yet. And the big one holding him, hes 45." Well at least he spared me.
The next day when we were in the car coming home from a field trip I could hear the kids in the back talking about something smelling.
Kid 1 - "You smell like grandmas house."
Kid 2 - "That means you smell like old people."
Kid 3 - "Ewww. I smelled old people before, and they don't smell good."
Not sure which old person they were sniffing, and which grandparents house they were referring too, so not sure who exactly should be offended by that remark.
Not to be outdone by my 12 year old. She had the best one yet. The dh went to play poker at a friends and the kids asked where he was. So of course we had to discuss his playing skills. I told them I was better, cause I beat daddy. So my 12 year old said, "Wow, he must be really bad then." Dang! Burned us both with that one. Couldn't have been more proud. Poor thing started to cry, but I reassured her she did great. She made us laugh and thats a talent hard to come by.