Author of the famous Harry Potter series JK Rowling gave a smacking reply to a Twitter user who passed an extremely “sexist” comment against Serena Williams who had just won the women’s singles at Wimbledon.After Rowling posted a tweet congratulating the ace tennis player for her big win, a Twitter user responded with a snide remark that “she is built like a man”.#SerenaSlam! I love her. What an athlete, what a role model, what a woman! — J.K. Rowling (@jk_rowling) July 11, 2015The author, who had only hours earlier posted a picture of hers and Serena Williams suggesting that she was a mighty fan of Williams, retorted to the spiteful comment with a witty response..@diegtristan8 "she is built like a man". Yeah, my husband looks just like this in a dress. You're an idiot. pic.twitter.com/BCvT10MYkI — J.K. Rowling (@jk_rowling) July 11, 2015If only the internet troll had seen her previous tweet, he might have saved himself from the embarrassment.