one of the problems i had a young father at work was when i got home from work my then wife would flip out on what the kids have been up to, like the saying wait till your father gets home, its too late saying something a few hours later when the kids have no idea what i was on about,
Like i said before, we are all adults and most have been through s--- to get here, just be nice and try to tell the young what is right and what is wrong,
My grandson who is 3 is a clever boy but does get upset if his mum says she is going to tell grandad if hes been naughty, we talk about it and hug and a kiss after the tears, usually works for a few minutes then hes back to his ways