It might be best to just ignore it and do your best to train your hardest, it is usually very bad idea to get involved in the personal relationship between a father and child, no matter how well intentioned. As a father, if one of my teenage daughters' friends tried to give me some advice on how to treat or raise my kids, I think one of my least likely reactions would be to take their advice to heart and change my ways.
"remove the plank in your own eye before helping your brother with the splinter in his own" to badly paraphrase some unemployed jewish rebel from 2000 years ago...
"remove the plank in your own eye before helping your brother with the splinter in his own" to badly paraphrase some unemployed jewish rebel from 2000 years ago...