OMG yes...
This was a large point of contention when I first came out to her. She always thought I was "compensating" for her weight gain. She became distressed when I would slip on my size 14 skinny jeans and she would don her size 20W's. She would order a summer dress and try it on only to dislike her image in the mirror and then become more so when I would put it on and it would fit me so much better (I'm larger up top than on the bottom of course).
It took her some time to realize that I'm just different and that's the way it is. I'm not doing this for her, I'm doing it for me and I have little control over what size I am.
She's ok with it now but it took time.