Lifestyle tips

I've been in a relationship now for about a month or so, and I really love my girlfriend. However, I'd really like to bring up my kink to her. In other words, I'd really like to introduce the idea of her fattening me up and encouraging me to fatten up.
I've brought up that I'd like to put on a little weight, but I'm not sure how to bring up a feeder/feedee relationship. It's not something I desperately need in a relationship, so I'm not worried about her saying "no," but it's just something I'm not sure how to really time out or word.
Any tips would help. She already is okay with me gaining a little weight and does like my belly, but I'd love her making me fat.

Ive tried this a few times sonetimes it works sometines it does not. Maybe try mixing things up by asking if she would be interested in introducing food during sex. Sometimes the words of explaining it to someone seem weirder or scarier than the actual thing.

When mentioning gaining weight to her, she responded by saying she thinks it would be cute for me to have extra fat. Which is good, but her main concern is my health in said fat. We are both very open about things and experimental when it comes to sexual anything. So we may try introducing food play first as suggested. I don't think she's necessarily feeder since we both tend to switch on and off of sub/dom. Hers is more dom and mine being more sub, so hoping that it helps her want to get me to gain more.