Yes, gay culture is represented as flamboyant and overly sexual.
You say, 'everything is sexualized,' but the ramifications are different. Heterosexuals have had years to adjust/re-adjust to their norms, values, and dynamics. Whether it is waiting until marriage or the stigma attached to having multiple sex partners, it is not expected for heterosexuals to **** around their entire existence. The appeal of sex in the media may be brought in to appear sexy and cool for straights, but society still expects the nuclear family.
Where as with homosexuals we're expected to alone or die of AIDS. We don't have a sense of family portrayed in the media in comparison to our straight counterparts. We don't have those norms or values possibly because we're told it is wrong to embrace our sexuality period. Like someone said, gay culture is still developing. Sexual activity among the same sex may have been around for a long time, but being an open community that is embraced is either new or foreign.
Lesbians are often depicted as attractive or two attractive friends experimenting. I'm not a girl/lesbian, but I get the feeling lesbian relationships aren't validated outside the gay community and the non-stereotypical ones are mocked much like gay men
My two dollars