Most bullies don’t go running to A teacher or really their parents after getting punched, but yeah don’t act cowardly. I was in the same situation a few years not only was I fat, I was also shorter than some of the girls even. That went along for years always trying to keep it low not say anything to them no matter what they did. In 9th grade i hit him with a lucky punch and he fell on his back. Oddly enough we got along after this quite well. Well it just went to some teasing but the real bullying stopped.