Not sure what to conclude on some of these responses. For me, the first time I had sex, it was not so much hurting the girl as I had real trouble penetrating her at all. She was older and made a comment saying, "Not everyone is compatible." I really was not aware at that time that my cock was a lot bigger than many others, I figured I didn't know what I was doing. Guess what? I didn't. No real foreplay, no getting her prepared, etc. Nevertheless, finally having the chance to have sex, I wasn't going to just give up and probably she never enjoyed it but I made sure to get it inside her anyway.
As I gained experience, I can say even thought I am almost 9" when fully erect (and not those b.s. underneath measurements) I have not had an issue with everyone woman accommodating me as long as I take my time. If it is a new partner, first you definitely have to warm the woman up with oral, lube, etc. Then, you simply test the vagina going slow to see how much she is comfortable with to begin with. Yes, if you go too deep too fast, there will be pain for many women and I have had some pushing back with hands or simply told, "You are too deep." But, I have also found as you begin gently fucking after a few minutes the vagina opens up more and you can go much deeper. Some women love it, some it doesn't nothing for. I think many love being stretched deep once they are really stimulated and I have had several women especially my wife cum from me having a very long penis. It is simply how you use it and your sensitivity to whom you are with.