noone is gonna talk like that under my roof

Nobody's gonna talk like that under my roof!
It can be generalized, that society's younger members, being those under the age of around twenty-five, use slang terminology, or swear, far more than people who are on the older end of the age spectrum. Many of those who are among the "older group" would like to think that today's youth are chaotic and without values, or that it is just a factor of immaturity, which is probably true, but there is more to the issue than purely immaturity. Many things come into play when analyzing the cause of difference in interaction and dialogue such as social standing, self-confidence, and levels of maturity.
First, it is important to understand societal perspective; In effect, one must analyze where society has placed a group of people in order to understand why the group's actions vary from everyone else. While it is true that youth do not have as great of responsibilities, it is also true that they, by societal definition, do not have as much freedom. During one's youth he can't be his own self, identity is scarce when he relies on mom and dad for everything, and therefore must adhere to their rules, and in turn, lifestyle. It is the quest of most young adults to break away from their parents and forge their own person. This quest often turns into rebellion, which for most families, encompasses swearing. Opposite of the youth in this situation, adults are expected characteristically to be more mature and respectable. Often times an adult would lose much of the respect of his of her peers if they cussed up a blue streak, while youth accept it as commonplace.