You see the circle there? This whole area is sort of awkward... I will show you why.
1. I call this the "underwear area" note the shape. This is also called the pelvis. The hip "socket" balls rest underneath the "ledge" there, and the shape of the top of the leg fits into that hollow.
2. This uh, "area" comes down between the legs... the legs don't pinch together, there is space there.
(I forgot to draw the butt, but you get the idea)
3. I'm reiterating how the leg attaches to the socket here.
4. Hanes underwear band.
Actually, take in the shape of the "hip area" as a hole, sans the legs, pelvis and sockets. See how it looks like a "D" placed on its side? This D is what connects the hips to the abdomen.