what did i do?

yesterday i was in school and we had to do a presentation in chemistry, i was alone bc this period was in group (the class is separated in 2 for a few hours) and in my group i don't rlly have friends, but tbh this don't bother me, anyway. a guy was alone too, he ask to his friends if he can be with them, his friends say no bc they already start and they couldn't take anyone else, and after one of them say (he was laughing) "go with Emma!" and the first guy said "uh no!" ??? what?? i wasn't mean with you all!! the only thing i do is not being super pretty?? being ugly in this society is worst that being in hell