What does the term “blue balls” refer to?

Your Answer: an uncomfortable feeling a guy can get if he's erect but doesn’t reach orgasm

Correct!
While it would be pretty funny to see a boy with blue pubic hair, “blue balls” refers to the discomfort some guys feel when they have an erection but don't reach orgasm. Also known
as "vasocongestion," this condition can be painful, but it does not cause physical harm and it goes away by itself. Unfortunately, some boys try to guilt their partners into having sex by claiming they're in pain (e.g., "you're giving me blue balls...). But a simple masturbation session would cure the displeasure in a flick of the wrist. Incidentally, girls can suffer from vasocongestion too.