Eating booty

Okay, I have a fwb who's been wanting me to eat her booty for a long time now. I'm talking months. I've never eaten booty but I've had mine eaten and it was great tbh (I was drunk but whatever). However, I'm nit entirely comfortable with the idea of it even though I know she's a very clean person and would clean extensively before hand. I've experimented with anal play with her before, but not eating booty. Are there any tips you might have to help me get over it. I'm not as opposed to it now, but I still need some tips/advice