I am a woman. I have to have my legs straight just as your wife describes. It is possible to orgasm with my legs apart (sometimes) but not as pleasurable or easy. Some women need the centering of intensity; if we spread our legs out, the intensity is also spread out. Do you see? So we could have a mild, barely noticeable orgasm with legs spread as you describe. Why choose that, when we can straighten our legs and keep all the intensity in one great location? By the way, has your wife had a hysterectomy? And has she had children? OK, because after I had a baby, I could FEEL my uterus contract inside my body during orgasm, and that is terrifically intense. Before I had a baby, it felt as though the orgasm was coming from my clitoris. The uterus contracts when a woman has an orgasm, and that is part of the pleasure. If she has had a hysterectomy, especially if it was recent, she will no longer have a uterine contraction during orgasm so she learns to have a different, more clitoral, orgasm. It could then be impossible to orgasm with her legs spread wide and no uterine contraction so of course, she would want/need to center the tension around her clitoris by straightening her legs and clenching inward. I have really hard, strong quad muscles because I have orgasmed this way most of my life. Let us know what you find out! Thanks for caring!!! You must be a great guy!!!!