I can only speak from my limited experience. I have only been with one bbc, my current lover. He is by far the biggest guy I have ever been with, and I was nervous at first. I am petite (5' 2 and 107), and I didn't know if I could handle him. But he was patient, let me get used to it slowly at my pace. I think that is the key, going slow. And we still go slow at first, even now. But I am able to take all of him now, and it feels amazing. He actually touches my cervix and pushes past it, which was a total new experience for me.