He goes to the doctor about this once a week and they still don't know what's wrong.....
hmmmmm..... usually your lymph nodes swell when there is a an infection of some sort. I would recommend that he see a doctor and have a swab done. It sounds like he needs to get checked out by a doctor, im sure he would respect you for wanting to use a condom or wait for the test results to come back. Keep in mind that many std's can be spread by skin contact on exposed areas not protected by the condom.
He needs to follow up on this.
It could be a staph infection from shaving or something, but if his lymph nodes are swelling every time he drinks, he needs to get that checked (and maybe stop drinking for awhile?) because that might indicate a deeper infection. They can biopsy the bumps, too.
AJ