You don't have to be skeletal, but you do have to have the rest, otherwise you're dating a pig and perpetuating their inferior genetic traits, or worse, rewarding the slovenly behavior that caused them to be so unhealthy.
Some women are ‘short-waisted’ which may or may not be in style (results in nice long legs but compresses the torso in dresses and blouses). Some are long-waisted which creates an elegant long torso but, unlike Michele Pfiefer, often results in shorter legs that may not look good in skirts. Some ladies have very narrow shoulders, some have broad. Flat chested or pendulous breasts. Problem skin (even with dermatology) or porcelain skin. Some have an “athletic build” and therefore a low waist to hip ratio like Jane Fonda had until she had ribs removed to get more of an hour glass look. We’re talking bone structure and genetics and hopefully stopping short of having ribs removed and not pigs or slobs. And note that the men who sought these model women were often not model men. Unfortunately, like the impossible advertisement above, men are being bombarded with impossible cosmetics standards for the male physique too but the women are way out ahead of them.