I have used many types of masks and have experienced many different types of problems. In your case, I would agree that maybe your hair is underneath the skirt or as is the case with one of my masks, it will leak if I smile, because of the creases on each side of my nose and when I smile it leaks. So your problem could be any one of several issues but I doubt that it is because you exhale through your nose. Any good purge mask of the right size should do the job for you.