Blue balls is a slang term[1] for the condition of temporary fluid congestion (vasocongestion) in the testicles accompanied by testicular pain,[2] caused by prolonged sexual arousal in the human male without ejaculation.[3] The term is thought to have originated in the United States, first appearing in 1916.[4] Some urologists call the condition "epididymal hypertension". The condition is not experienced by all males.[5]
Source. Wikipedia
https://en.m.wikipedia.org/wiki/Blue_balls
What is your age? Man i don't how to say this.... Do you get "excited" when you kiss? Erection? If so it is rather common with teenage boys.