Sexiest book character in the world. Ever. Sirius, aka Padfoot, and Snuffles, is Harry Potter godfather who got sent to Azkaban for a crime he did not commit. Before this, he was the hottest damn thing ever to walk the halls of Hogwarts School of Withcraft and Wizardry. He is not officially gay but according to a large portion of the Harry Potter fandom, he is Remus Lupin's bitch. Which is so not a problem. Sirius Black is the only fictional character that is sexy enough to fan-girl over.
Damn Remus, look at Sirius Black over there! He's not wearing a shirt.