Do you have a tighter hip on one side? If you lie on your back, place the soles of your feet together and let your knees fall out to the sides, does one hip open more than the other one? The one where the knee stays up higher and feels tighter might be compressed. The body compresses a joint to create greater stability, but longer term, this can lead to joint wear and tear. Stretching the groin muscles might feel nice but is unlikely to resolve the issue. Get this looked at. We can do this as part of our Pilates therapy and Neuro-Kinetic therapy skillset.