Testicular pain after 2 days w/o masturbation/sex. Vasoconge

Hi there.
Expanding the subject a little bit:
For the past 2 days, I didn't engage in any act of masturbation, nor sex.
I've been aroused a couple of times, due to my gf... But we couldn't do anything (family in the house).
Today I got aroused again... but now I have the proverbial pain in my testes (it's not the first this occurs).

What do you guys think this could be?

Thanks, anon.