I'm not a doc, but it sounds a lot like a torn meniscus or other cartilage damage. RICE (rest, ice, compression, elevation) may give you some temporary relief, but if it's been a month and it hasn't gotten any better, and it's interfering with your everyday activities, you'll probably want to get it checked out by an orthopedic doctor. An MRI would pretty much tell for sure what's going on in there.
Sometimes damaged menisci (and again, I'm just guessing that that's what it MIGHT be) can heal on their own, but only if they're in an area near a blood supply, and the tear is minor enough. Letting it go untreated could lead to more problems in the long run. I say kick your hubby in the kneecap, see how he likes it, then go see a doc. Just kidding about the kicking... but not the doc.