Blue Balls

I've actually been asked a few times: What are blue balls? Well in case you don't know but have been too ashamed to ask here's the definition of blue balls for you:

The term "Blue Balls" comes from a guy being stimulated sexually but not actually cumming. This is quite unsatisfactory for most guys and can even be physically painful although there is no proof that it actually causes any real physical damage. The term originates from the rumor that the balls can actually have a blue tint to them when in this condition. I must use the word rumor because I've seen no proof of this actually being the case.