Forget about the "Alpha": it is an outdated concept. Your pup is most likely peeing out of submission/fear. I don't know what your husband does to be the "Alpha" but maybe he is overwhelming to this already low key pup.
Try to avoid the following: elaborate greetings, leaning over the pup, looking straight into his eyes, facing him head on, fast movements. All these behaviors can cause him to pee out of submission. By the way: it doesn't have anything to do with "his balls dropping".
I hope you have not punished him for this peeing as he cannot help it; it is the ultimate sign of surrender and if you were to punish him, he will become confused and afraid of you and it will increase the problem.
Take it easy; he is only a 4 month old puppy. Enjoy him.