He was addicted to making personal remarks.
He spoke crudely and candidly about subjects that Philip had always tacitly impressed upon his children as being sad or unpleasant, and therefore unfit to be mentioned freely.
He asked indiscreet questions.
"How old are you, Father?"
"Hush, hush, little boy. That's a very rude question. You know you must never ask grown-up people their age."
"Why not?"
"Because it's very bad manners."
"Cousin Charlie asked Lily how old she was, the other day, and Lily didn't mind."
"That's different." Philip was at last beginning to learn that one could not put an end to Kenneth's enquiries merely by saying: "Come, come, you know Father doesn't like arguments."
"Cousin Charlie is a great deal older than Lily, and can say what he likes to her."