My husband and i have been married for over a year now, and we have 1 child together. My prepregnancy weight was 125, and after i had my baby, i dropped down to 104 pounds. With my build, and height, the doctor says i should be 125-130, so im underweight the weight i am now. My husband always gets onto me about my weight, and says that i need to gain it, and be 125 again. But just yesterday, he told me that my butt looks better at 104 pounds, then it looks at 125. I have an eating disorder, and hes telling me that! That is telling me in my mind that 125 is a no go, because my butt doesnt look as good.  When someone has an eating disorder, in my opinion you dont tell them that, or shouldnt even think that, because hes' giving me two wishy washy things hes saying. hes saying that i look better at 125, and i need to get back up to that weight, but than hes also saying that my butt looks way sexier at 104 pounds!! i dont know what to do, or what to say to him. he hurt my feelings so much, and now i dont see myself ever being the weight im supposed to be, because of what he said. im so sad.

When my wife exercises, her butt responds in kind (very firm and 'grabbable').  You weren't specific about what your husband likes about your butt.  However, it is possible that you could put back on your necessary weight AND do exercises designed specifically to lift and tone your gluts.

I agree.  Your partner is focusing on the wrong thing and it's very sad.  I hope you're getting help for  yourself.  It's very shallow to be focusing on your weight when he knows you have an eating disorder.