Disclaimer: I own none of these characters; they are the property of one JK Rowling. In Rowling we trust!

Author's Notes: Greetings, readers! I am quite appreciative of the positive feedback to my previously posted work ^_^. At the end of my last one-shot, I promised a multi-chaptered fic, and here it is. I didn't want to post anything that isn't at the very least halfway complete, as I cannot promise regular updates at the moment. This fic will feature more Sirius/Remus but will also include my second favorite pairing, Remus/Severus. Hopefully this will assuage your thirst ^_^. Enjoy!

He didn't need sensitive ears to hear them. The moment he opened the door he was assaulted by the sound of flesh meeting flesh, moans and grunts, cries for more. He was shocked, frozen in the doorway of the muggle flat he'd shared with Sirius for 5 years. He smiled brokenly, uncertain. Sirius had a thing for muggle technology; maybe it was that box-thing, the telly, playing those dirty movies. Remus held on to this faint hope as he moved toward their bedroom, his legs weak beneath him. By the time he made it to the bedroom, he was bracing himself against the wall, his stomach turning. The scent of sex assaulted him next, and he hoped against his better judgment that he was mistaken, that Sirius was just pleasuring himself. His hand shook as he pushed the door open. It swung open easily.

That broken smile was still frozen on his face as he took in the scene. There was no denying this, but his heart feebly tried, even as it shattered in his chest. Time slowed as he watched Sirius move, sinking over and over into the woman beneath him. She squealed and moaned and writhed, clutching at his neck and hair. Sirius responded by nuzzling her neck, thrusting harder, deeper. Standing there, watching, listening to Sirius grunt and that whore moan in return, Remus couldn't make a sound. In fact, he could hardly breathe. The room blurred and for a moment he was grateful for it. His knees gave out, sending his crashing into the table beside the door, gasping desperately for breath. There was a shriek from the bed and Sirius cursed loudly when the pair realized they weren't alone. Somewhere in the chaotic torrent of emotions coursing through him was the satisfaction of denying them completion.

Remus clutched at his chest, desperately trying to breathe but his lungs refused to expand fully. Pain ripped through his heart and he was vaguely aware of the woman running pass him and out of their home. All he saw of her was a blur of dark hair, tan skin, and a blue dress through the veil of tears that wouldn't stop flowing. Why the fuck couldn't he stop crying? Merlin, he was supposed to be furious, screaming, not collapsed on the floor, having a panic attack.

Having Sirius suddenly kneeling before him, clad only in black pajama pants didn't help. Remus trembled, sobbing now despite himself. Sirius was so close; he was practically choking on the scent of that woman. Sirius' face was flush, his brow contorted in worry and, was that regret? Remus could hardly concentrate on anything aside from breathing. Sirius reached up and touched Remus' face, attempting to wipe away his tears. He was muttering something, probably trying to soothe Remus, but all the werewolf could think of was how those hands had just been on someone else's body. He jerked back violently, lashing out to push Sirius away. Sirius was knocked off balance, hitting the footboard of the bed.

"Don't fucking touch me!" Remus shrieked, scrambling up the wall.

Sirius didn't move from his place, sprawled across the floor. Remus' chest heaved as he struggled to make his body obey him. He swiped angrily at his cheeks, glaring at his lover- former lover.

"W-Who is she, Sirius?" he managed to ask, leaning against the wall for support.

"Remus, I-"

"Who is she?" Remus demanded.

He felt his temper flare, something deep within him growled protectively. The wolf was waking, getting worked up and defensive. Things were getting dangerous. Remus closed his eyes, forgetting Sirius for a moment and focusing on reigning in his emotions. He was surprised by his reasoning. Five years with Sirius served to strengthen his patience, if nothing else, and now it was taking everything in him not to lose it. Apparently Sirius sensed this.

He signed, running his hands through his tangled hair.

"H-her name is Arianna… I met her a month ago-"

Remus' stomach plummeted. He sank back to the ground, hiding his face in his hands.

"A month?" he said, mostly to himself. The pain intensified unbelievably. He heard Sirius shift toward him, but he thought better of it and opted to stand instead.

"Yes, a month. She's a bartender at the Three Broomsticks. She seduced me-"

"And you went with her! You brought her back to our bed!" Remus screamed, glaring up at Sirius now, his nails digging into the palms of his hands.

"What do you want me to say, Remus? I fucked her, alright? I've fucked her in our bed; I've fucked her in her bed, in her shower. I fucked her at the Three Broomsticks and in the alley behind it. I've fucked her and then come home to fuck you, alright? I admit it!" Sirius shouted, running his hands through his hair again.

The blunt answer shocked Remus into silence. He supposed it was better than lies and excuses, but this agony was reaching indescribable measures. His breath was becoming short again, his tears were back full-force. He looked up at Sirius but the dog animagi refused to meet his gaze. His shoulders were stiff and squared, his stance arrogant and damn near proud. Remus knew this side of Sirius; this was him hiding behind a false bravado. His face was bare and vulnerable even though he wouldn't look at Remus. He was in pain; there was guilt in his eyes.

"Why?" Remus whispered, opting to focus on the ceiling instead of Sirius.

There was hesitation. Remus let his eyes slip closed and sighed.

"…Please… just… just fucking answer me."

"I don't have a reason, Remmie." Sirius answered softly.

Remus scoffed at the use of the pet name.

"You- you cheated on me… and you don't even have a reason? Come on, Sirius, there's got to be a reason. You slept with her behind my back for a month, and you don't even know why? " Remus could hear the bitter note in his voice but he couldn't bring himself to care.

"No."

Sirius' one word answer was like a slap to the face. Remus looked back at him and found the Sirius was facing the window, refusing to acknowledge Remus' grief. His anger flared again. Before he knew it, Remus was standing face to face with Sirius, pressing Sirius against the wall by the shoulders.

"Look at me, Sirius," Remus growled; Sirius refused.

"When did you become such a coward? If you're going to fucking destroy what we had, why not just tell me? Huh? Why'd you have to do it this way? Y-you could've… just told me, Sirius. You could've…you could've…"

Remus collapsed in on himself, crying in earnest all over again. He cursed himself for his weakness, but this fucking hurt. He'd never felt so vulnerable, so broken, even when the wolf within him shattered his bones and ripped his flesh. He felt useless and unworthy, even though Sirius was at fault. Never before had he questioned whether Sirius was happy with him; he never had reason to doubt it. Now he did. He was vaguely aware of Sirius hesitantly wrapping him in his arms and he hated the comfort it brought him. It made him hope there was a way to fix this, despite everything.

"I… I can't give you a reason, Remus. I don't have one, and I'm not going to try and come up with excuses. I'm sorry… I'm so sorry."

"…Do you love her?" Remus whispered, dreading the answer.

"I…I don't know." Sirius answered, feeling Remus tense against him but unable to bring himself to lie.

After a moment Remus nodded against Sirius' bare chest. He stepped out of Sirius' embrace.

"Do you… do you still love me?" he asked feebly, looking directly into Sirius' eyes. The pain in them intensified and Remus' heart clenched again. Somewhere deep down he knew the answer before Sirius even spoke the words.

"…I don't know."

A/N: Alright! Chapter one! Chapter two should also be posted today or tomorrow. Feedback is much appreciated. ^_^ Until next time! Muahh!