johnxyz:
If she is not into it, she's not into it. If you tell her you are into it, it is a rejection of her size. You either have to choose between your girlfriend, or choose between the feederism community.
I don't agree, frankly. I believe you can love - and make love - to your girlfriend regardless of your attraction to fuller forms.
Liking big women doesn't necessarily mean that you can't like slender ones either.
However, you did mention that she's attracted to your emaciated form too. That's a somewhat different issue.