Cass was a bit surprised when he heard the tone of Harry's voice, and stayed for the hell of it in the sitting room for a while. He was overly curious though (perhaps why he made a good Auror) and couldn't help himself but had to follow.
He was rather surprised when he overheard Harry say he didn't like lying. And more surprised when Pansy asked him if he wanted to tell him the truth.
'And what truth would that be, exactly,' he said, popping his head in, and looking from one to the other. 'Hello, darling,' he then said to Pansy. 'You're looking as gorgeous as ever. Now which one of you are going to tell me this truth of yours?'