However, as with snapping
hip syndrome, inflammation may develop in the joint, and there can be swelling if a tendon or
bursa sac becomes aggravated or damaged. According to the Library of Congress' Everyday Mysteries, excessive popping may lead to some soft tissue damage, although the effects can be minor.
You shouldn't have to worry about any popping going on in the hip joint. If the noise can be eliminated by adjusting your sit-up position, consider making a change.