Fuck it, none of ya'll know my IRL identity, so I'll just be honest with this shit.
My gf has put on a few pounds. Probably more than a few now.
Last night she told me she looked in the mirror and felt disgusting. I told her she wasn't. She said she was really frustrated about the weight gain. I suggested workout tips, diet tips, etc, talked about how I'd managed to lose a few pounds recently, etc. Constructive, motivational advice. I mean, I'm not the one who brought it up. She brought it up, so I thought it was fine to give her some pro-tips. I told her I still loved her, still thought she was cute, etc. Told her I wanted to lose 5 pounds myself and we could do it together.
Today she called me and told me that she was really sad and that I hadn't given her the support she needed in that moment. Not sure what that was supposed to be. The gist of it was she wanted me to say that I'm just as attracted to her as I was at the beginning.
That would have been a lie. Being perfectly real, the weight gain has made her a lot less attractive to me. I still have a lot of fun with her, and I still love her. But those last few pounds have definitely pushed things past the point where I don't really feel the urge to initiate sex rather than just pass out or watch a movie or whatever. But there is no earthly way to tell her this. It's so demonic, friends.
You might not know this, but has your girlfriend either had weight issues in the past, or, perhaps more acutely troubling for her, is this the first time she's really put on weight?
lulz at people telling you that stewing on something for one U.S. night is a BFD, BTW. Y'all either soft as fuck or been out the crazy game too long.
e: You mentioned you'd been having a disinterest in being intimate recentish, is this in conjunction with that or was it the reason for it?