Refusing to listen to "killer queen" because it was too gay.

Someone couldn't ever admit that he was wrong to a woman, particularly not to a girl.

So I said, 'why did you buy the American sliced cheese, you hate all of the additives?' and he refused to believe that there were additives. I litterally pulled out the American cheese and read the ingredients list out, then compared it to our usual cheddar, which just listed milk, but he refused to admit that a teenage girl knew more than him.

Eating pussy.

My father once chose course of intravenous therapy over intramuscular injections because apparently exposing your butt to a nurse is not manly enough

Refusing an umbrella. Ok, be wet then.

Not sure if this counts, but one guy I knew would boast about how he never drinks water. It was a matter of pride for him that he only drank soda. I know he was lying because I'd seen him drink water, but better not tell him that.

Refusing to drink beer from a glass.

Back in my country, bottled mineral water used to have a pink cap when it was non-carbonated, and blue cap for the carbonated one. I guess, I don't even have to finish the story, at this point everyone can imagine... But yeah, in primary school I had class mates who refused to drink the non-carbonated one, saying it's "gay water".