Cindy probably knew that.
OK, your answer is helpful.
It simply wasn’t done within my family, for the reason you cite. “Recoil in horror” might be a bit strong. “Recoil in bewilderment” might be more like it.
I think that Bristol Palin’s “tell-all” book is unnecessarily trashy, regardless of the oafishly parvenu behavior of the McCains.