So let's talk about oral....

Rachel
Hey ladies!
So my boyfriend really likes to 69, but I don't like it so much. I'm extremely self conscious about everything below my waist ever since I had my surgery to treat my ovarian cancer. He says I have nothing to be insecure about and he loves to eat me out and finger me but I get extremely uncomfortable in that position. In fact, I'm extremely uncomfortable with him eating me out just in general. 
How do I tell him I don't want him to eat me out without it sounding rude or without it sounding like I don't like it because he's not good at it?
Thanks!!!