Whereas the word gay acquired a new meaning in the recent times and stopped there (earlier, the meaning was being happy, now ironically it means being some who loves the person of his own sex, and it’s certainly not a happy situation, given the rampant homophobia in society), the word queer is still hasn’t lost its sheen and mystery. Earlier, queer meant everything not normal, then the gay right movement appropriated the term and made it an umbrella term for any kind of sexual situations which are not normal or mainstream.
The key word here is normal, or more precisely normative. There are things normative and everything that’s not normative is queer. Normative refers to structures which are mainstream and given, structures which feed the basic functioning of a certain social situation. Therefore, marriage between a man and woman is normative, because, as Marx said, family is the key unit in running the mechanisms of a capitalist society. Marriage also signify distribution of power, where the male, breadwinner dominates the other. When two male, breadwinner decide to live together, they upset the balance.
Cinema is queered when it deliberately moves away from the classic blockbuster formula. Cinema, as a source of entertainment, has constructed a structure for itself over the ages, and when a film deliberately decides to disrupt this structure, it can be called queering; it has nothing to do with alternative sexualities per se, through the representation of alternative sexualites play a major role in queering cinema.