Seamus Finnigan had always loved Christmas. When he was a lad, before he headed off to Scotland and school and destiny and all of those other things he never thought much about but were always in the back of his mind, Christmas meant their ramshackle castle was suddenly full of second cousins and great aunts and friends of friends who happened to be passing through. Everyone would sing and sing and sing some more, especially his parents. It seemed to the eight-year-old Seamus that all of wizarding Ireland was being fed by his O'Connor grandmother--not to mention the half of Muggle Ireland that was being fed by his Finnigan grandmother at the large farmhouse in the next village.
When Seamus first went away to school, he was terrible homesick. Now even though Seamus usually was talking, he did know how to listen, and he was a perceptive young lad. He could hear from what they didn't say that his roommates Harry and Neville didn't miss their homes much at all. Of course, Ron had little reason to be homesick since nearly his entire family was at Hogwarts anyway.
Which left Dean. Dean was so quiet that Seamus had to listen very hard to hear what he didn't say. But in the days leading up to Christmas, he spoke of his own family's Christmas traditions, about how he and his siblings and parents would pile into a motor car early in the morning and drive from West Ham into Brixton, to his grandmother's house. And he would see second cousins and great aunts and friends of friends who happened to be passing through, too. And his grandmother cooked and cooked and cooked. Dean, it seemed, was homesick for rice, which they almost never had at Hogwarts.
Seamus was mostly homesick for music. Not nearly enough singing at Hogwarts for his liking, especially at Christmas.
In second and third years, Dean and Seamus exchanged some small presents before leaving for their holidays. Dean would usually give Seamus a drawing, and Seamus would give Dean more quills and ink to draw with. Sometimes they exchanged owl posts over the holiday break, and Seamus' sisters (of whom he had many, all older) would tease him about having a boyfriend. Seamus didn't think they were especially funny.
In fourth year, they were to stay at school over Christmas. Seamus found he didn't mind, because he could spend the holiday with Dean, and with Lavender, who was fun to kiss. Dean was more fun to wrestle, even if he almost always won.
That year, Seamus' mum sent a parcel full of presents, at the bottom of which was a box from his cousin Danny, who lived in America now. Inside were two hats that looked like wizard's hats, except they were red with white trim and a white pom pom at the top. Dean, who knew about such things, said they must be Santa hats. Seamus immediately put one on, then, after thinking briefly about how it would look against Lavender's blonde hair, reached over and planted the other one on Dean's head.
Dean just laughed at him, but Seamus could hear what he wasn't saying.
Seamus had rarely had as good a time as he did at the Yule Ball. He spent the entire evening with his best mate and a very pretty girl. Seamus, being the youngest and the only son, was very good indeed at being the center of attention. Somehow he never made other people feel that they were competing for his notice. He reckoned he had enough love for everyone.
Fifth year proved him wrong. Justin wanted all of Seamus' love and attention for himself. Seamus had never had a real boyfriend before, so he thought maybe that was the way it was supposed to be. He brought Justin home to the castle at Christmas, but it wasn't quite as much fun to show it to him as it had been the summer before when he was showing it to Dean. Besides, Justin couldn't sing.
That year, Seamus talked even more, to drown out the sound of what Justin wasn't saying. And what Dean said, with only a look.
During the weeks leading up to Christmas sixth year, Seamus wasn't much in the spirit. He loved Dean but Dean didn't seem to love him and there was nothing that could be done about it. He would sit in his bed at night and sing melancholy ballads to himself very softly, the way his mum did when he was a small boy, but still sleep would not come.
He hid the Santa hat in the bottom of his trunk so he couldn't see it. There was no sign of Dean's hat, either, which Seamus was secretly glad of. Hermione said that hats couldn't mock you but Seamus knew better.
Then there was a dance and a kiss and more than a kiss and much more than a kiss. It turned out that Dean had loved him all along but Seamus had spent so long trying not to hear that he had forgot how to listen.
The next morning, after breakfast but before the train ride home, Dean and Seamus put on their well-hidden Santa hats and went outside to throw snowballs at the Slytherins. Hermione was running about with a camera and snapped Seamus standing on a snow bank, his arms around Dean's shoulders. It was this picture, of a romance hours old but years in the making, that Seamus carried with him forever after, to remind him of the rewards of listening.