This question came up when I was noticing what normally is said in this forum and what a girl told me when we were having sex. She told me that when she was on top I was hurting her coz my penis was reaching her uterus(I think that is possible since I read many say about hitting the cervix). It felt like I was putting more inside her so I guess she was right and I was deeper than we were in missionary(is this what you say when the man is on top?). But I read in many posts here that when the woman is on top, it hurts less because she can control the depth of the penetration. I put some thought to it and ,according to this, the man should stay still while the girl makes all the work. That`s just not as fun as when you`re also moving your hips(BTW what do you call the movement of back and forth? pounding?). So next time she`s on top should I hold still even though I think that is a lil weird? What is the anatomical explanation for being deeper while the girl is on top(I guess it shouldn`t make any difference)? What about doggy style: does it goes deeper? If possible I would like to know the relationship between depth and sex position.