Well, if you are really thin (in the lower abdomen, at least), the pubic bone can be pretty close to the surface, right at the base of your cock. So, I suppose if there were something hard in a woman's body right at that point, I guess some 'black 'n blue' result might be possible. However, I've never been with a woman, even very slim, who has bone similarly right at that point. All that I've been with seem to have 'padding' there, with the female pubic bone being somewhat more 'buried,' as it were. But I guess we all, of either gender, come in all shapes & sizes (to put it mildly). Just my own 2cents here.