A male friend is wearing a hat that you think is a poor choice for headgear. Perhaps it contains the logo of the wrong sports team, the wrong beer brand, or the wrong college mascot.
You say, "Yo, dawg, that hat is gay. Take it off." And punch him in the arm.
The hat itself is not gay. In fact, unless that college mascot is a picture of two intensely muscled men engaging in a sexual act illegal under Virginia law, it's probably painfully straight.
You should say, "Dear friend, your hat represents a cause which I cannot in good conscience support. If you do not remove it, you risk threatening our distinctly non-homoerotic friendship." Or, alternately, "Yo, dawg, that hat is so straight. Keep it on to maintain your veneer of excessive masculinity." And, uh, the arm punch is a little wishy-washy. Steer clear of actual contact unless it's in the context of testosterone-fueled sport.
You and a male friend are undressing young women with your eyes. Your glance locks upon one who wears a particularly provocative outfit, but she does not return the glance despite your best efforts to honk your horn and whistle belligerently.
You say to your friend, "Man, that girl don't even give me the time of day." To which he responds, "Damn, bro, I heard she was a lesbian." You say in reply, "Man, that's so gay."
The young woman herself is, in fact, gay. You got that part right for once. Your response, however, is lacking. You should say, "My dearest friend, that woman is gay. She engages in acts with other women that were not recognized even to exist in Victorian England. She is unattainable, so we should objectify her sexually to annul the threat to the institution of masculinity." And then you should make lewd gestures to ensure continued dominance over women.
You greet a male friend with a high five, and certainly not with a hug, a kiss on the cheek, or any physical contact that could cast into doubt your manliness. He is wearing tight dark jeans, a tight pale lycra top, an earring in his right ear, and has a crew cut.
You say, "Yo, homeslice, why you dressed so gay?" And punch him in the shoulder.
You should say, "Oh my lovely friend, you crazy boy you, you are dressed in a style that may lead some to believe on first glance that you prefer a lifestyle that may lead to a relationship that could not lead to marriage under American law. I will be spending a pleasant evening on the town with you, and your outfit may lead others to believe that I associate with homosexual men, perhaps even carnally, which threatens to emasculate me and endager my status as heterosexual (and thereby alpha) male." To which he will reply, "But we're going to a gay club tonight." And you will say, "Oh, right. So it is Thursday." And then make out.
I hope that I have lubricated the wheels of social change and gotten the ball rolling towards increasingly unambiguous male discourse. Young men, join arms and fight for proper use of language in the streets, in the bars, and in dark corners of the dance floor! Then again, some people might take your bodily contact the wrong way.