What have I done?

[classical retro]

I made some tracksuit bottoms, which shrank when I washed them. (Thumbs up to the prewash fabric brigade.)
Luckily I made them too big so now they fit, but too short. I decided to narrow the inside leg seams from the knee down and have a  perfect left bottoms leg, however not on the right.
I undid the inner and outer right leg seams and when trying them on for the refit realised that somehow the right back piece does not hang straight, even though I cut a pair, the right side skews towards the back leaving a gap between front and back at the bottom right side seam of about 5 inches. The ribbon trim hangs straight and is parallel with the right front leg piece.
 
Can anyone tell me what I have done?  I did think perhaps I should take all the right side seams out completely and the back seam and start again.  What do you think? Sorry I haven't a photo, it's a step too far at the moment but if you think it will help......

Thank you
CR not so now!
 

[Kwaaked]

Sounds like the right leg may have been cut off grain.

[Ohsewsimple]

I would have taken both seams in rather than just the inside but yes sounds as if it wasn’t on grain  to start. 

[BrendaP]

Undo the left leg seams and see if the same (in reverse) happens.

If both back pieces skew towards the back then yes, they were cut off grain.  If one skews to the back and one to the front then it's a problem with the fabric, think twisted tee shirts!

I hope you manage to get a better fit than that shown on the McCalls model

[Morgan]

A thought -

Get the paper pattern pieces out again.  Look at the position of the grain line on the back piece and compare it to the one on the front when the pieces are pinned together as you have them.

Back legs can be tricky because depending on how much roundness,(or not)and where it is around the bum, hips and hip flare, will affect how the back leg hangs.   Shape not just measurement is a major controlling factor with trousers.   You may well have cut it correctly as per the pattern and it's the way it's designed.  Fitting adjustments, especially those that affect the pitch of the leg, can shift the grainline angle on the torso section.  A quickie check is that that the grainline on the leg usually springs up from the centre of the base on both front and back - after adjustments have been made.

[classical retro]

Thank you so much for your help.
I couldn't work out why one leg was fine the other one not when I had cut a pair, I guess I mustn't have had both parts of the fabric on the straight grain as I thought. When I was looking closely though there was a pleat/fold in the back going from the waistband down on both sides, but disguised more on one side than the other.  I'm going to have another careful read of your second paragraph Morgan with the trousers on and pattern pieces pinned to understand it.

The fabric came from Fabworks and it is sweatshirt weight, one of their better quality fabrics three or four years ago. I'm loathe to touch the left leg seams specially as it means taking off the trimming. If my quest for perfection gets the better of me, I may do it BrendaP. It's that toss up between it'll do, they're only for leisure against do it properly. Mind you if I do take both seams apart it means I can take them in on both sides. Looks like I've talked myself into it.

Don't need them till autumn/winter, so to the back of the UFO queue they go. No doubt winter will come and I'll be cursing for not doing them sooner.   Such is life.
Thanks again.

CR