This is a question so that I can help my boyfriend

five months ago I treated with metrogel for bacterial vaginosis. Since that time almost everytime I have sex w/my boyfriend he gets an irritation on the top of the shaft of his penis. When we use a condom, he does not get the irritation. My gyno says that there is nothing wrong with me but I definitely think that there is something wrong with me and that I am causing my boyfriend this irritation. Has anyone else had any similar experiences? Can anyone offer any advice?

The irritation is like a rash and when it heals the skin peels off and is sensitive. He treats with anti-fungal treatment and it goes away. We just don't want it to happen at all. Any advice?