As a Parent of teenagers (one pre Teen at 12 and another at 15), I have found that I have a pretty good tolerance. I tolerate their Music, although I think it's awful. I tolerate the fact that my kids are attached to their phones, but so goes the World. I tolerate attitudes that come with the teen years - I remember my own issues all too well. I tolerate the hair styles and clothing options - honestly, that shit has never mattered to me
What I don't tolerate from my kids? Lying, Cheating, Stealing & Bad Manners
Lying is awful. One small lie begets another, and so on. It is the precursor to a life that leads down wide paths to no where. IMO, lying is addictive and leads to other awful habits down the road.
Cheating is the easy way out with many kids. They cheat on tests, cheat themselves out of hard work, and cheat themselves out of doing things the right way. I get on my kids a lot about cheating themselves from doing things the right way all the time. You think it's okay to do things half assed, and you will continue doing those things half-assed the rest of your life - Family, Work, Morals, etc.
Stealing - never had a problem with this from my kids, but stealing is wider than just taking someone's XBox game. It's stealing other people's idea's, taking credit for shit you did't do, etc, etc. I hope I don't have to deal with this with my kids. I might beat them to a bloody pulp if I ever catch them cheating
Last but not least, Manners. From the time my kids were old enough to sit up in their High chairs, we were teaching them good manners. I never really learned these things as a kid, but somehow I was smart enough to watch my Parents and learn just enough to get by. Having good manners as a kid will get you a long way in life - meeting friends, getting that first job, relationships, and in everyday life. My kids aren't perfect, but we are working on it.