The idiomatic expression "blue balls" refers to a slang term for intense sexual arousal without release, causing physical discomfort or pain in the testicles due to prolonged erection. Full definition
Those stars and blue ball jars in the window are just great. (findinghomefarms.com)
There's so much football that you're left with a massive pair of blue balls once you realize that there's no actual football in it. (silverscreenriot.com)
The names of the artists who created the pieces were also written in blue ball point pen on the wall. (en.wikipedia.org)