Who says that one of ten friends is gay?
It sounds like an even more misunderstood version of a finding from Kinsey. He found that in a particular period of time 10% of the male subjects had had exclusively male to male sexual activity over a period of 3 years. Kinsey wanted to repeat this survey each decade to find if the ratios of same-sex vs opposite sex encounters changed over time.
Kinsey point blank refused to talk about something as undefined as Sexual Orientation. He strictly looked at sexual behavior.
There has never been a time when 10% of the male population have identified as "gay".
A group of friends is not a random selection of the population. Gay men socialize with other gay men.