Cheech's uh.. problem

So today we discovered that Cheech's penis wasnt going back into his sheath. We ended up taking him to pet emergency since no regular vets were open and didnt want him to suffer with it. The vet said its fairly common in adolescent rats and they took his temperature which was normal and then took one of those cotton balls w/the wooden stick and used the cotton ball end (w/a bunch of lube) and pushed the penis back into the sheath and held it there so that the skin would unrestrict. The doc warned us that it may or may not happen again and sent us home w/3 of those q-tips on the sticks. Well, by the time we got back and went to put him in the cage, he had another erection so we let him go in the cage with his brother long enough to eat and get some water before doing what the vet had done to him not even an hour previous. We did that at around 10 (had left the ER vet at around 9) and at 11:30 Cheech had another erection. Only this time he's sore and grouchy and wont let us do it again. Should we just leave him be and let it try to resolve itself? We plan on calling our regular vet in the morning and maybe they can figure out why he keeps having this problem.