I think Ethan may have Anterior Pelvic tilt. It's when your pelvis rotates forward, sticking both your abdomen and butt out. It's caused by excessive sitting without exercise and can be fixed
Pelvic Tilt, Pelvic Thrust and Hip Rotation in Transgender women in a Nutshell
Pelvic tilt? How can I fix this! : r/flexibility
HOW TO FIX UNEVEN HIPS (ANTERIOR PELVIC TILT)
Laboratory Practical Exam Flashcards
Looking at pelvic tilts -The hips only tell you part of the story
Pelvic Tilt, Pelvic Thrust and Hip Rotation in Transgender women in a Nutshell
Pelvic Tilt, Pelvic Thrust and Hip Rotation in Transgender women in a Nutshell
Anterior pelvic tilt even after stretching and strengthening : r/flexibility