Be careful, Ed...that's how rumors get started (*cough Larry Stylinson *cough).
Harry and his ever-present headrag/headband were on hand to support Lou's book The Craft, where he was seen hanging with bandmate Liam Payne and his girlfriend Sophia Smith, as well as his sister, Gemma, and exes Caroline Flack and Kara Rose Marshall.
Where were the other 1D lads? Well, Niall Horan was hanging with the Queen at Buckingham Palace. No biggie.