I too initially was into being a feeder. But in the last few years, with the opportunity for me to gain weight now I feel I would prefer to be a "feedee" whether or not my "feeder" was into mutual gaining or not.
I was always the feeder or at least wanting my girlfriends or wife to gain weight.
I myself happened to gain weight along with my ex girlfriend many years ago when we moved in together and found that the mutual gaining was so erotic and something really special.
Currently with my wife we have both gained good amounts of weight several times and still find this to be the most intimate and sexy thing ever.
I guess everyone is different but weight gain is the stem of a lot of erotic things for me. Watching my wife gain weight is probably the sexiest thing in the world for me!