We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Took one of my smaller male Labs for a long walk this afternoon. He decided to hump a large male Lab, and, on his third try, the big homophobic one got truly pissed and gave him serious, deep bites just above the eye and on the nose. When we got home, he ran straight upstairs to our bed, curled up, and bled on our pillow. It is amateur vet time. I don't think the dog is exclusively gay - he just doesn't seem to discriminate, like a monkey: when he's in the mood, he doesn't care. This dog is supposedly spayed - wrong word - I mean castrated, or neutered, so maybe that explains it.
Growing up with several, our black labradors were often in similar trouble for this behavior. As the NJS says, it's usually about dominance, not sex.
In our case, living in a city where dogs only got to run free in the park (in a country where people preferred dogs to people, so city life was more bearable for a dog than in, say, NYC), our male dogs literally never got the chance to roam out of our sight. So, although they aggressively leaped on other male dogs, they were pretty clueless around females. The only conclusion we could draw from it is that if they see more of their male competitors than potential mates, they get better at asserting their dominance over other males than mating.
Years later, working on Capitol HIll, I observed the same phenomenon...
From dogs to war... our Sunday evening family bonding time is watching the Military Channel, pretty awesome looking corner shot gun...can even fit a grenade launcher...Awesome goes the most martial kid.. http://www.cornershot.com/
Had a great dane once. Got him from the lbreeder too young, he peed like a girl. Tried to teach him to lift his leg by propping him up against a step, or a tree. We lived in Laguna Beach--close to the gay beach. Taking him for a walk in that neighborhood was always worth a good laugh!
Talked to my ex (vet), and he said dogs hump 90% of the time because they get horny. A neutered male will still hump but not as much as an intact male. Females will hump females, spayed or not. He basically said it feels good and the urge is common often brought on by another dog's scent.
The dominance part comes in when the humpee doesn't like being humped. He naturally tries to get out of it - not necessarily with biting unless the humper continues.
It's not like a case of establishing pecker-order. Some dogs like a particular toy or pillow. I had a wire-haired terrier that used to hump our cat. The cat didn't care at all and stood patiently waiting.
Dogs aren't gay. They just get horny.
I hope your little fellow is doing fine. Labs are too sweet and it's sad he ran into a grouch.