I have a similar problem in that my mouth is tiny and I can't open very wide. If I try to go down on a guy my teeth wind up scraping depending on how big he is. My first bf? Forget it. He was far far too big. My second was smaller but I found that because he was circumcised, he didn't taste all too well, so I didn't do it to him often. I guess maybe I should just stick to tongue work, sucking and using my hands on the next guy.