The four boys slowly approached the great castle, taking care not to be seen. This early in the morning, a small group of sixth year students meandering unattended up from the lake was just asking for McGonagall to seize them. Once they were under the strong, curving arch of the entrance hall, Sirius dropped back from the other Marauders. He had different plans. As quietly as he could he crept across the huge patterned tile floor, but this didn't prevent James seeing him. To Sirius relief, his best friend merely gave a knowing wink behind Remus' back as Peter scampered around, vying for James' attention.

Little freak Peter, thought Sirius as he ducked beneath a smaller arch and made his way to the old charms classroom. In there, he knew, was an abandoned teacher's office, the small wooden door neatly tucked away in the back left corner. He entered the classroom and looked around for the almost hidden office, which James had told him about after he had to clean out the classroom for yet another detention session. ''It's perfect mate,'' James had chuckled, ''Ideal for your little… adventures.''

Sirius' shoes made a soft clicking noise in the echoing space. Reaching the door, he gently pushed it open, turning the metal handle with great care so as not to disturb anyone passing in the corridor. He wished he had had the forethought to bring the Map; he would have been able to see if anyone was approaching. No-one was in the office, but that was fine with Sirius – he could wait. He had half an hour to spare before his Potions class began, and he would happily not attend Potions with the doting Slughorn in favour of his planned activity here. He seated himself on the desk chair and settled in to wait. Realising it was a little cold, he cast an acclimatisation spell. His girl would appreciate that.

After a while, she arrived. Sirius purred in appreciation as he stood to meet her. She was looking particularly ravishing today, her long hair artfully curled and falling over her shoulders in glossy waves. Her face was fixed with its usual challenging smile, as if to say, ''Is that the best you can do? I dare you to show me better.'' For Sirius, her red lips smiled a little wider, blue eyes sparking a little brighter, and he adored her for it. But what he loved most was the way she spoke for herself, how she always fought her corner and how she never gave in. She may appear as though she was, but Marlene McKinnon always had the upper hand. There were ulterior motives to every decision she made, even if she wasn't the brightest girl in the school. This attracted Sirius beyond belief.

It was a fact that would surprise the entirety of the school of Hogwarts, but it was indeed a fact that Marlene McKinnon and Sirius Black had never made love. The few people who knew that they hadn't done the act (James, Remus and Lily, who was Marlene's friend) were surprised like this because it seemed impossible that a girl could attract Sirius Black without taking her clothes off, or growing big bosoms, neither of which Marlene had ever done. Her bosoms were pert, B size things, her clothes only came off in front of her roommates, and even then she was embarrassed. How had she attracted the notorious womaniser Sirius, let alone get into a serious relationship with him?

Before Marlene, Sirius had kissed every girl in the school, with the exception of older girls who made him feel inadequate and Slytherins who made him want to regurgitate his last meal. This was something he was intensely proud of, but then he had kissed Marlene, after following her for weeks on his best behaviour, and suddenly it all melted away, and he realised what was really important to him, what really anchored him to this world. It wasn't his family – he despised them – it wasn't his hopes and dreams, it wasn't even James; it was Marlene.

So now they met up most days in various places around the castle before classes, to spend some real quality time together. For Marlene Sirius would wait. For now, he was content to hug her and kiss her and end it at that. Merlin – he felt honoured just to know her and see a side no-one else saw. He wouldn't, couldn't, pressure her into anything. The thought of causing her pain gave him a greater pain than anything else.

''Morning, Sirius my love,'' she beamed coming towards him and pulling him onto a sofa.

''Marlene…'' he whispered, awed as always. She raised her perfectly shaped eyebrows at him, expecting a compliment.

''You know that you are too beautiful for a compliment, Marlene.''

''I suppose you never had to compliment your girls before,'' she teased, with what Sirius thought to be the sexiest wink possible, ''You would just have them in a bathroom and leave, right?''

''Those were the ordinary girls, darling. But you are better than ordinary. You are absolutely fantastic.''

''And what does that earn me? A month of courtship, then two times and then you leave?'' she continued the little game.

''Marlene, you do know that I am hopelessly in love with you, right?''

''The great womaniser Sirius Black, in love? The devil in disguise who's had every girl not in Slytherin, in love?''

''I think you are in need of proof, Miss McKinnon.''

''Of what, Mr Black?''

''My love of you.''

''Is that so?''

''Or perhaps you don't need proof – you just want it…''

''Desperately, Sirius.''

With those hushed words, whispered throatily by his ear, Marlene turned her head and they shared one of the best snogs of their lives. The world fell away until it was just the two of them, adoring, respecting and totally loving one another.

When Sirius reluctantly broke away to leave for Potions, Marlene watched him go wistfully, her heart thudding and her breath catching. He went with a final heart-melting glance, and she heard the door to the charms room click shut. Crap, she thought, I really have fallen for him.

Putting a tentative hand to her now warm, puffy lips, Marlene departed to her class.