I think that some women want different kinds of nipple play on different days, kind of like me. My "local" regular, for example. Sometimes, she's content with (relatively) gentle nipple play. Other times, she demands nipple atrocities. The time I remember most vividly, I was down south enjoying some DATY, with my hands up on her chest doing some moderate breast play. "If you pinch my nipples," she suggested, "I'll come." So I did a little pinching. "Harder." Increased force. "No, pinch them HARD." Well, after a while, I thought I was pinching pretty robustly, but apparently not. She kind of lost patience and put her hands over the backs of my hands, with her thumbs on my thumbs, her forefingers on my forefingers, and began to exert the pinching force she was trying to get me to do. It was brutal! I couldn't understand how that wasn't actually damaging her. But she did in fact come, and afterward, I saw no signs of bruising or other injury. It's a good thing she did that, to demonstrate to me just exactly how hard she wanted her nipples pinched. I'd have never done that by myself, no matter what she said.
Just goes to show: what a dull world this would be if we were all alike.