Severus felt dizzy. Dizzy from the want in Remus' claim, from the way Remus, almost easily, held him against the wall. Severus could feel the tip of Remus' cock as his entrance, and he felt as if he was to die from lust and anticipation. Severus gave a slight smile, relief and happiness evident in the way he looked at Remus.
Then there was a burning pain, as if his body had decided to split in two. 'Hurts,' was all he was able to say, then burying his face at Remus' neck, as not to let him see exactly how much. 'Yours,' Severus murmured against Lupin's skin, 'My Remus!' No matter the physical pain, the claims felt like promises they made to each other. The pain had to wait.
Severus breathed slowly, just as he had learned when he was subjected to a Cruciatus, to be able to manage the sharp pain that shot through him. It hurt like hell, but there was an element of pleasure in it - the pleasure of having given himself to the wolf, contrary to all sense and old hatred. Groaning softly in Remus' ear, Severus' relaxed body allowed Remus to slide further in. Being filled like this was odd, strange, painful, good. Very good. As the intrusion became less painful, his arousal spiralled. Severus looked at his wolf, taking in his expression of deep desire. 'Yes,' Severus repeated as he tryingly began to move with Remus. 'I'm yours.'