Why do you call Lady GaGa by her birth name? Are you trying to show us all how smart and informed you are? That you did your research (or just a cursory google search)? It seemed pretentious and annoying.
You know what’s really annoying? When butthurt fangirls use words they don’t understand. For instance, addressing people by their birth name is, quite literally, unpretentious. On the other hand, it’s the very definition of pretentious to insist that everyone call you Lady Gaga when your name is just plain Stefani with an f.