I believe the expression 'cum like a race horse' stems from when a high dollar horse's semen is collected. Most often, a large 'glove' with a tube on the end is slipped over the horses penis as it 'mounts' either a gelding, or a fake (wooden frame) mare. When the horse orgasms, the semen runs down the tube into a collection container, now days usually plastic. Seeing it being done a long time ago I remember that a gallon sized container was used and it pretty much filled it on one ejaculation.
Race horses used to be the only breed or type of horse that artificial insemination was performed. Now it is commonly used on other horses, cow and farm animals especially when cross breeding or pure-bred breeding high dollar animals.
Cumming like a race horse does mean a large amount of semen in an orgasm. You're right about men usually only producing a little over a teaspoon full, but there are exceptions to the rule and even to the time or number of times too.
wow...I learned something today. That's a good thing. Reading that I can see the sense in the saying now.
It's amazing how much you can learn when you get into reading trivia and odd news articles. If my memory serves me right (and it may not always do so, until the doctors finish cutting another cancer off) the study of words and phrases backgrounds is something like entomology - whatever they call it, it's fun.
My favourite is the phrase "Cold enough to freeze the balls off a brass monkey." This is a very old British Royal Navy expression and greatly predates the idea of making monkey shaped statues out of brass. It goes back to the early days of shipboard cannons.
Beside each cannon was a brass triangle screwed to the deck. This held the ready use cannonballs, one in each corner. The triangle was so well made that once the balls were placed on it, they were very tightly packed and it took a real effort to get one off. The ship's deck had to be nearly vertical for them to fall off. They were made out of brass as it didn't contract or expand in the cold and heat as much as iron did. Add in the fact that a helper who was good for very little was known as a 'monkey' and you get positions that relate to the cannon like - powder monkey, young boy who runs between the cannon and the powder store bringing back small kegs of gunpowder; and brass monkey, the brass triangle on the deck.
The cannon balls will stay safely secured in the brass monkey until such time as the weather gets a few degrees below zero and stays there for some hours. In those conditions, it gets cold enough for the brass to contract enough to make the cannonballs actually pop off the triangle. Not the kind of conditions to be out in the weather in, if you can avoid it.
Thus, 'cold enough to freeze the balls off a brass monkey' means it's well below zero degrees outside on deck. Kind of chilly.
