Is it normal that my 46 yo gay male friend is still in the closet?

He won't even admit to any of us that he's gay, and he's our housemate! We are all cool about it. He sneaks off to have dates with his lovers, he watches gay porn online and hides it from us (but we know) and he won't bring his boyfriends home. It's so obvious that he's as gay as Anderson Cooper. We live in a liberal country so there is no reason for him to still be in the closet. I think he needs to show some balls and start living a "real" life. This is 2012 and being gay is acceptable now (at least it is where we live). He is a professional man and he would not be censured by his boss or work colleagues or anything like that. He would not be subject to gay bashing etc. He also lies more than most people and I think that he's been living a double life for so long that lying has become a habit, like a drug user. I don't blame him, though. Growing up in the seventies and realising you're gay would be tough.
Note that two of the housemates have 'fessed up to having Bipolar Disorder and for being on special medication for it (Valproate and Seroquel). I would say it takes more balls to admit to mental illness than admitting you're gay. More stigma to be mentally ill.