Some progress on the tights, using the same technique as for the lingerie: strategically place some strips underneath the top fabric and constrain them to the body. I've also added a new pattern piece for the crotch and put an elastic on the centerline in MD to make into get really close to the body. As you can see, unlike in the sitting image above, there's no fabric spanning between her buttocks anymore.

-- I'm not mad at you, just Westphalian.