Alastor hated being touched, and invasion of personal space, however, he had no problems doing so to others himself because he found thier reactions "entertaning" this especially applied to you... his love for invading your space doubled when he found out that, just like him, you had ears and a tail... he casually walked up behind you one day, running his fingers through the animal-like ears on your head as he spoke

"My dear, how come you never told me you had ears and a tail?"