A/N: thanks to all those that have reviewed, I'll update as soon as I can.

They spent the afternoon under that shaded oak tree, as the sun didn't get them at any point in the sky because of the tree's size. They talked about anything and everything. From serious issues like the future to silly little things like their favourite food. They laughed a lot. But they were whispering about some things, delicate subjects.

"The marauders, Moony, Wormtail, Padfoot and Prongs" she repeated after he had told her his story of last year at Hogwarts, were he and his friends had become illegal Animagus, so as to accompany there friend Remus Lupin in his painful transformations as a werewolf. He smiled as she wondered at him, "You really are a trouble-maker behind doors aren't you?" he just laughed at her.

"Sirius, can you really turn into a dog?" she asked. He smiled and winked at her before standing up and checking to see if his brother or anyone else wasn't near. His body then changed and moulded in the most unbelievable way. It spun at the same time too as Rosalie marvelled at the transformation. And then it was over. There was a large shaggy black dog sat on the ground were Sirius had been, wagging his tail. He gave a little bark. She doubled over in laughter. Standing up, the dog leapt at her. She gave the hair on his head a ruffle and stood up. It ran around her legs, showing off. She smiled as she watched him jump about.

"Unbelievable, absolutely unbelievable. Sirius black you are full of surprises" he barked at her once. His eyes were still that handsome gray. She picked up a stick from the ground and threw it,

"Fetch boy!" she said to him in a tone of voice you use with babies. He just sat there and she could have sworn he had raised an eyebrow. He flicked his head up as if to say 'you fetch it'. She just started laughing again. When she looked back Sirius Black was stood in front of her, flattening his hair down.

"Fetch? Oh thanks" he said sarcastically. She just smiled and ruffled his hair, despite him being taller than her.

"I think I prefer the dog" she said. He growled at her in his dog voice and she laughed again. He then joined her.

"Sirius Black, you are a complete mystery sometimes, do you know that?" he laughed a fake laugh at her,

"Do I know that? My dear Rose, I do it on purpose, I am after all, the great Sirius Black". He said bowing to her. She laughed and sat back against the tree. He fell beside her.

"I can imagine what you're like at school, with the infamous James Potter" she said. He smiled

"Yes, we Marauder's certainly have a laugh" he admitted

"I would love to meet them, the Marauders" she told him. He looked at her,

"Maybe you will one day, I don't know if mother will allow them to the wedding, but maybe the reception" he thought aloud.

"Maybe" she repeated. He tried to change the subject,

"Remus doesn't like me telling anyone about him, and well, my friends won't thank me if you rat us out, so don't tell anyone okay?" he asked, she smiled slyly at him,

"Oh Sirius, you obviously don't know I am the great Rosalie Lambert, well know assassin. I can use this to my advantage" she said standing up and pulled the bobble out that was holding her hair in a pony tail, like she was taking off a disguise and posing. Sirius laughed at her, before standing in front of her and raising an eyebrow,

"Are you challenging me?" he asked in a fake innocent voice. She scoffed sarcastically,

"Bring it on, Chihuahua boy" she replied and he howled in his dog voice. She laughed and he growled at her. Her smile dropped suddenly and she whispered

"Shut up Sirius!" he frowned at her and said,

"What?" before he noticed she was looking behind him. He turned to see a very happy Regulus strutting up to them like a peacock. As he walked past Sirius he smirked and when he got to Rosalie, he kissed her on the cheek and put an arm around her waist. She smiled at him, but Sirius had seen her true smile, it was breath-taking and this was just stretching her lips. She seemed quite uncomfortable in his arms. Sirius tried not to glare at his brother in envy, but he couldn't help it.

"Were you two just arguing?" he asked, his tone was cocky and he was most certainly showing off. Sirius couldn't tell whether it was because he knew about Sirius's feelings or because he had a beautiful blonde girl that he could show off. Rosalie did a fake laugh, it was an awful sound compared to her actual one, but Regulus didn't seem to notice. Sirius was suddenly surprised that Rosalie had shown him her true self, and had been real around him and not with his brother. He suddenly didn't feel so envious of him; in fact, he pitied the fact that his brother was being fooled.

"Of course not, Regulus, we were just having a joke. I haven't seen you all day, what've you been up to?" she asked in a kind of babyish voice. Sirius had to stop himself laughing, which wasn't hard after a warning look from Rosalie. He put both his arms around her waist and seemed to cradle her. She tried not to show disagreement to this.

"That's because you've been out here all day, doing something stupid that you girls do, singing of whatever. I've been sleeping until gone three when mother came home and she wanted me to organize clothes and stuff for the wedding. You were supposed to be there but I told her it didn't matter" he lent in and whispered in her ear,

"I'll deal with you later". Her face lost colour. She looked at him, hoping she didn't mean what she thought. He smiled darkly at her, a smile she would never forget. Sirius noticed her panic and became worried, what had his brother just said? She lent back towards him and pretended to hug him, her face away from Sirius,

"What do you mean?" she whispered, trying to keep the fear out of her voice,

"You know what I mean, don't wear short sleeves tomorrow" she gulped

"Are you going to hurt me? Beat me?"

"If you deserve it…" he trailed off and pulled away from her completely. She was white and looked quite scared. Sirius became worried and wanted to reach out for her, but Regulus was watching him carefully, more scowling than watching. Sirius returned it,

"Don't you think you should go sort them things out with my mother, love" he said aloud to a Rosalie who was stood, looking out of place. She nodded her head in agreement, and walked in the direction of Sirius. She mouthed 'Don't' to him and as she walked past whispered,

"Your secret is safe". He wanted to grab her by the arm and ask her what had just happened, but he didn't know what consequences it would have. He watched as she walked away, pulling her hair back up into its pony. He thought he saw he shiver, he hoped not. He turned to see his brother leaning against the tree, lighting a cigarette. The brother's just watched each other.

"Pretty hot, huh?" Said Regulus, pointing to the girl as she walked out of sight,

"Yeah" replied Sirius

"She's weak too" he told Sirius, this make the eldest brother tense up, "She scared of me, can you see it?" When Sirius didn't reply he continued, "It's pathetic; if she thinks I'm bad now, wait till we're married"

"Yes, I imagine it'll be quite a shock" Sirius said through gritted teeth,

"You're jealous aren't you?" Sirius didn't reply to the question, just tried to fake a frown, inside he was nervous. His brother knew the truth. He continued, "I see it every time you look at her, don't think I'm blind. You're gagging for her. Well I got news for you bro' she's mine. Up until I die, that girl is mine. So keep away" he repeated his fiancée's words. Sirius accepted his challenge,

"Or what? You'll make me pay?" he spat

"You forget, I'm three years, I'll be a death eater, with my little bitch by my side, I will have the power to make you disappear in the blink or an eye, no questions asked. So take my advice, she better still be a virgin in three months time, Sirius" and with that he dropped his cigarette and walked away. Sirius glared at his brother. Perhaps he was wrong; perhaps his brother really could bring the wizarding world into hell.

He sighed; Rosalie was the cleverest, most beautiful, funniest, and nicest girl he had ever met. He could go on but he already knew there weren't enough words in the world to describe her rightfully. She did not deserve his brother or the future ahead of her. He knew that he was going to do everything in his power to make sure that she got as far away from his sibling as she could, even if he had to sacrifice his own heart. He cared for her too much to let her stay; knowing she would be hurt, emotionally or physically, she was too pure, too innocent to have either. He loved Rosalie Lambert too much to watch her suffer.

A/N: in case you didn't know, Regulus and Rosalie can't kiss until the wedding day when they have there first kiss as is tradition, like they cannot make love until after marriage. Also, please don't hate Rosalie, I know she is leading Sirius on, but you'll see why in future chapters. And it'll be about 20 or more chapter's long but please don't let this put you off. Review appreciated x