My husband and son are not talking

Something very awkward happened between my husband and son a few weeks ago. My husband doesn't knock. He believes since he pays the bills he can just open our sons door. He doesn't do that with our daughters. Just our son. I'm like "You're gonna walk in on him jacking off if you keep doing that". Plus our son is 18. I think it's dumb he will give 13 and 15 year olds privacy but not an adult. Well... He walked in on our son doing something very.... Weeiiirrrddd. Basically our son was dresses in female cosplay. Pink wig and all and was dancing for someone on his laptop webcam while they called him a slutty girl.... There was a time when he watched Blue Clues.... Yeah my husband walked in on that and now they wont even be in the same room as each other. Son walks in, husband walks out. Husband walks in. Son walks out. We haven't eaten a meal as a family in 3 weeks. I get its awkward but it's been 3 weeks! I miss eating together as a family and they won't even simply TALK to each other or even be in the same ROOM. What do I do?