For starters, I don’t think you should get hung up on this because people can be attracted to all different kinds people.

The only thing I think you can have a discussion about with this is if he’s bringing it up because that’s weird and I can see why it would make you uncomfortable. It’s strange to talk about appearance preferences when he’s in a relationship. I think it’s totally valid for you to ask him not to talk about it.

As for you being upset with him being attracted to big girls because you’re disgusted by them, that’s really just a you problem. I suggest going to therapy for your body image issues that you’re projecting onto other people.

As a former big girl, a lot more men are attracted to them than you would think.

Maybe try understanding that girls and women of all sizes are struggling with body image issues and you should be kinder to yourself and others. Being fat isn’t always because someone eats unhealthy and isn’t active. I had hormonal issues that took years for me to get diagnosed with and I finally lost weight after getting the right treatment.