He always felt a bit like a prat as he watched her.
Not only was she a year younger than he was, she was also Harry's girl. Everyone knew that - even Dean, blighter that he was, knew that when he agreed to date her.
To be fair, it really wasn't Seamus' fault that he found her so enchanting. She could have covered up that gorgeous red hair which could light a fire in any self-respecting Irishman's blood. She could have frowned, hid her intelligence and fire.
Perhaps if she had, he wouldn't have been sitting there in the common room, mooning after her like a cow and wondering if she'd ever give him the simple mercy of a smile in his direction.