You cannot be serious man !! (see what I did there). McEnroe was penalised many times in his career for his conduct and was fined tens of thousands of dollars. Sexism is nothing to do with it. Serena broke the rules she knew existed and then got annoyed when she was penalised for it just like any other player would be, male or female. She's just a egomaniac who doesn't think the rules should apply to her. (IMO)