In werewolf form, Remus Lupin ran through the forest.
He was a little sore after his fight with Serius, and his adrenalin was pumping round his body after his encounter with Buckbeak the Hippogriff.
He growled softly, enraged suddenly.
He began sniffing at a rock and was all at once fascinated by an entising scent...it smelled like another werewolf, ready to mate!
He let out a howl, excited.
After a moment, a female howled back, and he rushed to her...
When they met, Lupin faintly recognised her scent, but it didn't matter - his hormones were surging through his body, and desire overcame him.