Tight Hip Flexors

I have freakishly tight hips - i sometimes cramp up just sitting in indian position. However I have no issues squatting deep, no issues deadlifting heavy, no issues running sprints at maximal speeds, etc etc. The only time my hips have a negative effect on me is static stretching and sex (i’ll sometimes cramp up during the act). Whats going on? Is this an issue I need to correct or is this some sort of an adaptation, or does my tightness stem from somewhere other than my hips?