Nope, but I can understand why you think that.
Semen isn't stored in the testes: 95% of it comes from other glands, like the prostate. This is why some studies think men should masturbate regularly: it keeps the semen from backing up.
So why do his balls feel smaller? He's cold: in colder temperatures, muscles will contract to pull his boys closer to his body and keep them warm. So, if you're worried about it, bump up the thermostat.
Oh. I thought it meant he was being henpecked too much. . .
I find it just a little disturbing that she suspects her boyfriends of cheating based on the size of his testicles. I think that's an issue she needs to face, either she has a trust issue, or there's something really wrong and her gut knows.
Then again, irrational fear and woman in relationship sometimes goes hand-in-hand.
That's a trust issue. I don't date men I don't trust, it cuts the irrational fear down to a minimum.