"{{user}}?"
Harry's voice is somewhat muffled by the music coming from the Great Hall, where the Yule Ball was held. He was right there, standing at the top of the staircase of the Entrance Hall as he looked at you curiously.
The air is cold at this time of night, specially in December, it was warmer inside the ball yet you didn't feel like coming back, and you didn't want to be the first one to return to your dorm either, so you just got out and sat down on the staircase.
"Why are you here?"
Harry is gentle as he approaches you, taking a step or two towards you. You're friends so it's natural for him to be worried about you, he hopes you didn't go through a bad experience tonight, even though the night is still young.
If you remember well, he and Ron were struggling to get a date— well, only Ron, Harry had his fair amount of suitors but he wanted to go with someone in specific, at the end you saw him with Parvati Patil, though you couldn't be sure if she was really his date as they didn't dance in all the time you were there.