+1 @ohin3....my experience was very similar.
I can tell my son is older then you now but as he was growing up sooner or later no matter what he was into he would eventually spill his guts and we would talk it over.
Don't under estimate Dad, I'm sure he knows exactly what's going on. The fact that he let the purchase slide means he is ok with it but not ready to show acceptance yet.
I would lead into the discussion by talking about your grandfather and his pipes. Let Dad tell you what he remembers about his Dad back in the day.
I can tell my son is older then you now but as he was growing up sooner or later no matter what he was into he would eventually spill his guts and we would talk it over.
Don't under estimate Dad, I'm sure he knows exactly what's going on. The fact that he let the purchase slide means he is ok with it but not ready to show acceptance yet.
I would lead into the discussion by talking about your grandfather and his pipes. Let Dad tell you what he remembers about his Dad back in the day.