My first girlfriend was a virgin, she had never had a finger in her or even a tampon. Her pussy was so tight I couldn't even get my smallest finger in at first without causing some obvious discomfort for her. Eventually she did get used to that and at times would take as much as two fingers as deep as I could get them, but two was her limit. That made it pretty difficult when we first had sex. It was obviously pretty painful for her and I wanted to stop because of that but she kept telling me to keep going. It was like that every time we had sex. Eventually she cheated on me with a guy who was a lot smaller than me and I guess it worked out better for her. I do remember that every time we had sex my cock would be sore the next day because she was so tight.
My girlfriend after her was also a virgin. We only had sex once and it was a similar situation. She was in pain, started crying, and I stopped even thought she told me to keep going. We stayed together for a little while longer but no real sex and the other problems with our relationship made it not worth my time.
The third girlfriend was the complete opposite, it made sex a lot easier and more fun.