I have been wondering about this for a while. I have seen a lot of posts from ladies that a prod in the cervix is equivalent to a kick in the nuts. I have occasionally experienced women who have had this problem in certain positions, but I have also experienced women who have got on top, and humped away like mad with maybe three inches just not going in, but no apparent problem with bashing the cervix. In the latter case the pain/worry seemed to be all mine. I am sure other guys will know what it is like when a partner's weight is supported just on your knob rather than coming to rest on your body. Is there a reason for this?