My boyfriend is pretty well endowed. I am very petite. When we have sex, pretty much no matter what we do, it starts to hurt after 10-15 minutes. It's like a burning sensation in one specific place, and after that it takes about 36 hours for my vagina to stop being sore. We use lube, so that's not the issue, and I've used the same lube with other guys without problems, so it's not an allergy thing either. I think he's just too big for me. Is there anything that can be done to make this better?