Posted 4/13/2018 7:58 PM (GMT -5)
I agree with Susie that it is always best to see a physician for a new and aggravating condition that lasts more than a few weeks.
That said, you mention that crossing your legs on both sides is problematic but that you have no pain with forward ambulation not with managing stairs. You do not mention your age, but most people in late middle age develop a degree of stiffness of the hip joint capsule - the connective tissue is less subtle and becomes more fibrotic with thickening, often with inflammation. Adhesive capsulitis is a diagnostic term. Bursitis is another possibility.
Do go to see your primary care physician for a differential diagnosis or an appropriate referral to a specialist. He may refer you for some diagnostic blood work or imaging. A physical therapist could address any simple connective tissue problem diagnosed.
Best wishes in health,
Karen