When I first zipped up this muslin and looked in the mirror, I thought "Holy weird flare, Batman!" Once I spread the super-tight thigh area, the whole thing looked much better. I then made a plumb line and the Little Mister helped me re-draw the side seam. Below is a closer view of the new side seam and spread thigh area.
The middle fabric is a black and white striped mid-weight denim I got from Affordable Fabrics years ago, too. I bought a lot of this one (about 6 yards) so if something goes wrong with the pants construction, I still have plenty to try again. My only concern with this fabric is that it may come off as too dressy for my job's "dress down" day.
The third fabric is a dark vintage denim. It is 100% non-stretch cotton and is still a bit stiff after 3 pre-washes. There is enough for 1 project.