Remus moaned loudly, barely managing to keep his hips still. "Siri... oh fuck..." The sight and the feel of Sirius sliding down his length was too much for him. "I... I'm going to... to..." he warned, or tried to, but 'cum' wasn't a word that was really part of his vocabulary and 'orgasm' seemed far too formal at a time like this. Besides, it was so many syllables. And then all words were too much for him as he felt his brain shoot out the end of his erection.