Regulus Is A Lovesick Puppy But Wont Admit It - Tumblr Posts

Regulus getting out of the Gryffindor dorm, meeting Sirius, Remus and Peter on his way out:

Sirius, defensive: What are you doing here??

Regulus: Studying. With Potter.

Sirius, opening the door, to see James sitting on his bed cross legged, with a dreamy smile on his lips, his face and neck covered in lipstick stains:

Remus, chuckling: Studying huh.