Well, silly though it may be, some people still DO take offense at swearing. I guess one comparison you could make is wanting to not have to view shock porn when you visit your friends' pages on Facebook. Barring freedom of speech? Eh. It's more or less a polite request so that you don't have to run and get eye bleach whenever you want to view their status. That person may still go and put up shock porn on other pages and other websites...it really isn't a hindrance of free speech so much as adhering to a set of social norms to be nice to others. Your aunt's and your own are clearly in contrast, but is it so hard to cut back on the swearing, bearing in mind that it makes your aunt uncomfortable? It'd be a small pain I for one would be willing to undergo to make another person close to me happy.