I think parents sometimes treat their teenager like an adult that has to be responsible and sometimes like an irresponsible child depending on how the parent wants to be a killjoy and prevent the teenager from doing something the teenager wants to do or to make the teenager do something they don't want to do. If the teenager wants to do something fun like partying with their friends, the parent will treat teenager like an irresponsible child who is not old enough or responsible to do such a thing and if the parents want to make the teenager do something the teenager doesn't want to do like a big household chore or saving his allowance money (as opposed to buying something nice) that's when the parents will treat the teenager like he has to be forced into adult responsibilities and not have whatever fun the teenager wants.