Gaining

I had a gf who lost weight. It was definitely a buzz kill while she was losing, but when she hit her target weight* and stayed there for awhile I eventually adjusted.

Not sure if the same will happen with your bf, but there's a good chance. If you care about each other, hang in there!

* She was still chubby there, just not as much as before. If she had actually gotten THIN I may have had a problem!

Introduce food into your sex.Let him tie you up and feed you,fantasise during sex about getting really fat..it'll turn him on and with your high metabolism,you'll stay slim.

Obviously guys are visual and us FA are not only visual but like the feel also.

This is a suggestion kind of like a band aid fix...... Us FA's who are into weight gain have good fantasy type imaginations so why don't you role play with him and tease him with fat talk about how fat your going to get and possibly even pad and stuff your clothing. Maybe even get a high end fat suit and role play out you getting even bigger than you probably could get in real life. He might get some crazy satisfaction from just hugging you and seeing you that big not to mention our seductive fat talk you would be doing.

Sounds to me like an immaturity problem.

This guy got lucky and got a girl to indulge his fetish, but the experience has gone to his head and now that things have to change, he's thinking he doesn't want to not be able to enjoy a fat and gaining gf so he's going to cut off his nose to spite his face, mistakenly thinking he can just ditch you and find another girl who will continue to satisfy him.

Most likely he'll selfishly leave and break your heart without much concern, only to come crawling back in the following weeks/months saying how sorry he is and how wrong he was.

Or maybe I'm just being cynical. :/

Either way, I'm sorry that you have to go through this, I hope it works out for the best for you.