Why do gay people always have to act gay all the time?

I've always wondered that, myself. Of course, its not all gay people, but a lot do seem to behave stereotypically. A lot of people do though. Look at your average bunch of 'lads on the piss'. They all wear similar clothes, drink fizzy lager out of bottles, speak in a loud 'football crowd' sort of voice and will inevitably start singing Angels by Robbie Williams before the night is through. People feel safe as part of a tribe. When we identify with others, we behave in similar ways. People are afraid of individuality.