I have a weird question. I can't seem to get into the advanced siddhasana pose. I'm flexible enough (I can get into lotus pose-padmasana easily)so that ain't the problem. It seems that my lower legs are just too short. I can get the heel close to the perineum (or yoni-opening in my case) but then my knee comes forward like I'm sitting in a crossed leg position. Also, resting the heel at the opening almost seems impossible because the heel turns upward and rests against the clitoris. When I bring my other leg into the action, the knees come forward even more and the whole thing looks weird; certainly not the way you see it in pictures.
Does anybody recognize this? Can there be other reasons for this except physique?. All advice and tips are greatly appreciated.