I have personally experienced a very well reviewed provider here on Eccie giving me the option of BB, right from the very first meeting. She even offered BB Greek. I politely declined and asked for a cover. She rubbed lube all over me and THEN put a condom on.
During Greek, the condom naturally started to slip off from the tightness and the lube. She told me to keep going, and I almost had to fight my way off of her to go to the bathroom, wipe all the lube off, and put on another condom.
Considering this was my first encounter with her, and she has well over 30-40 reviews on Eccie, I highly doubt this was an isolated incident. Honestly, it scared the shit out of me and I have never returned.