Relief washed over Harry and he gave Susan a smile. A moment after he realised that he wasn't going to have to hide in the bathroom, he was startled by how amazing she looked. Of course, everyone was dressed up like they were going to meet the Queen, but he didn't think he'd ever seen Susan in a gown.
"Well! We wouldn't want that," he answered with a grin. "Did you just arrive?" He knew better than to ask a woman if she was at an event alone. For some reason, they didn't appreciate it. It was rare that Harry had a date to these sorts of things, so he wasn't exactly sure why it was offensive to some people.