Bacterial Vaginosis is a fairly simple issue really. And yes you can get it from a guy. They could have slept with a partner previously that had it and they passed it to him. The only thing is that they can not detect it on a guy. The way I found this out was my ex-husband was cheating on me and I kept getting BV. I spoke to my doctor about it and he said that I most likely got it from him (before I knew he was cheating) and that we were passing it back and forth to eachother. Doc suggested my ex get treated but he wouldn't do it. When I left him, I got better and haven't had one since. What you need to do is find a doctor who will treat him for a bacterial infection. Explain to him that you are not dirty and that it is a just a natural part of life. Kind of like a yeast infection. I am sure he will be understanding about it. It's not life threatening and will go away soon.
I hated those days for me. But you will feel better in no time.