I have two boys aged 13 and 15. Both can be difficult at times (as all kids can) but my eldest really isn't a bad kid at all. He's never been in trouble at school or outside of the home, is top set in most of his school subjects, is generally well mannered and well behaved and has kept a paper round up for almost two years getting up religiously at 6am 6 days a week to earn his own money.
Now yeah, some times he can have a bit of an attitude. He's 15 after all, he knows everything there is to know about everything. DP just cannot see this for what it is though and makes a massive deal out of it each time he does it.
Last night I was working night shift and got a text from DP saying DS had been chucking a football around in his room and had refused to put it in the shed when told to do so. My response was "cheeky sod he is, I'll be having words tomorrow." DP then began sending text after text about how out of order DS is, what an awful attitude he has, how he's now burnt all his bridges with DP and how he needn't go to him for help with anything ever again and that's it, he's finished with him
. My response to this huge over-reaction was "ok - he's a prat for chucking a football around the house and is out of order for refusing to do as he's told but he is 15 - 15 year olds tend to have an attitude, it's not highly unusual (and certainly not bad enough to talk about disowning him!!!). DP decided to share with me that no, 15 year olds do not generally have an attitude, no kids he's ever known at that age have had an attitude and his own angelic kids never showed such an attitude and he's upset that he "has to live with it" 
AIBU to think that yeah he's right about the football and DS was out of order to disobey a request but it's not highly unusual behavior for a lad of his age??