Calming Melody -- I would certainly call you a plus-sized rider, but that doesn't mean I think any less of you. I would also call you a brunette that wears glasses between 17 and 20 years old. It's just what you are. So what? If I had to send someone to find you, they need a description.
But when people insult others about their appearances, that's just wrong. There is a difference between stating what is and calling someone names, whether it be "fatty" or "beanpole" or "four-eyes".
It's also about how you take it. When I got my glasses in grade school, everyone called me "four-eyes". Keep in mind, I was never popular in the first place, so this just gave them extra to target me with. But, it never stuck. Know why? Because I was just so darn happy to be able to see, they could call me four-eyes all they wanted and I would just smile with the wonderfulness of being a four-eyes. I thought it was great!
Oh, and I certainly agree - I don't see that you would be hurting your horse. :)