"You were away for too bloody long," Sirius growled as he pushed Remus against the wall, right next to their front door.
"Sirius…" Remus breathed, but he was silenced as his boyfriend kissed him greedily.
"I missed you," Sirius said accusingly when he finally pulled back.
"I know. I missed you too." Remus rested his forehead against Sirius' and pulled him closer. "Have you eaten?"
Sirius nodded. "Yeah. I considered waiting, but you stayed away forever. I hate you."
That made Remus smile. "Of course you do. Leaving you hungry, how dare I."
Sirius softly kissed his neck. "I'm glad you understand your mistakes."
"Let's go to bed then, right?" Remus smiled.
"Yes." Sirius squeezed him, then reluctantly let go and took his hand. "Did you have dinner?" he asked, remembering to be a good boyfriend as they were halfway up the stairs.
"I'd have protested if I hadn't. Hungry werewolves, remember," Remus said, stroking Sirius' hand with his thumb.
In the bedroom, they quickly undressed until they were in their pants and then got under the blanket, cuddled up together. Sirius kissed a line over Remus' collar bone.
"I thought of you every night. Wished I could communicate with you," Remus said softly, threading his fingers through longish black hair.
"You could have apparated," Sirius pouted.
"You know that was too risky, love. They could have noticed as they came to check on me."
"Why do they need you?"
Remus huffed. "Because I'm good at what I do."
"Yes, of course. That's not what I mean." Sirius sighed. "Can't they just let me come with you?"
Remus leaned a little back to look at Sirius with a smile. "Don't be ridiculous. A spy taking his boyfriend on a mission. What sense would that make?"
"What sense does it make that their top spy is a werewolf and disappears for a few days every month?" Sirius retorted.
Remus kissed his forehead. "I've done this before for the Order, spying on the werewolves on Voldemort's side. It gave me the experience, and what other job would they hire me for? At least I can be useful as long as I work for M. So it makes a lot of sense," he explained patiently.
Sirius whined. "But it's not fair. It takes you away from me."
"And I always return." Remus softly kissed his lips.
Sirius buried his face in Remus' shoulder. It had been more than a week. It just wasn't fair. "What if one time you are away for so long that you hardly even know me anymore by the time you're back?" he whispered.
"Oh, Sirius." Remus kissed his hair and wrapped his arms more tightly around him. "I promise that will never happen."
"I love you." Sirius' voice sounded very small and he tried to drown himself in Remus' scent, pressing kisses over his chest.
"Come here, you." Remus pulled him up so he could face him and stroked his face, then kissed him again. "I'm yours."
Sirius nodded, still looking a little miserable.
Remus kissed him again, soon getting carried away as he pushed Sirius on his back and trailed his hands all over his chest. "You are so ridiculously beautiful," he panted as they broke apart for air.
Sirius gave him a small smile. "Did you never have to spy on anyone who looked better than me?"
Remus chuckled. "Never."
"Good." Sirius kissed him again, his hands wandering down Remus' back until he was cupping his arse under his pants.
"Get those off," Remus growled.
Sirius obeyed, pushing Remus' pants down to halfway his thighs, then rolled them over so he could pull them off and get rid of his own.
"Merlin," Remus mumbled, drawing Sirius back into his arms to kiss him, both of them rolling their hips and moaning every time their cocks brushed against each other.
Suddenly, Remus felt hot tears fall on his cheeks, and he pulled back with a frown. "Sirius?"
A sob went through Sirius' whole body and he couldn't speak, just pressed his face against Remus' neck and cried.
"Love?" Remus asked again, uncertainty clear in his voice.
"I'm sorry," Sirius whispered against his skin. "I'm being ridiculous."
Remus softly stroked his back and let him catch his breath before he spoke again. "What are you thinking of?" he asked softly.
"I can't lose you. I always want to have you here, close to me in my arms, but it's impossible." New tears were rolling over Sirius' cheeks as he looked up at Remus.
"My Padfoot," Remus whispered, hugging him tightly to his chest. "I love you. Don't be afraid?"
"I'm sorry," Sirius said, shivering and clinging to Remus. "I'm ruining the mood."
Remus smiled and kissed his temple. "Knowing us, we'll find it back soon enough." He was silent for a moment. "Do you think you could do it? Pretend you're someone else all the time, reveal the truth and play a role?"
"To come with you?" Sirius hesitated and brushed his tears away. "I know I'm often a little too honest, but... I'd do anything." Again, he hid his face away against Remus' shoulder, feeling embarrassed.
"It would be harder for me," Remus admitted. "I mean, to stay in character when you're around. To act like I don't know you when you're right there. As long as people are watching, I couldn't touch you, and even when no-one is around, we might get caught."
"I know," Sirius sighed.
"But I would love it, you know. Slipping into your room after a long boring day and just lying in your arms." Remus smiled, a little shy even though Sirius wasn't looking at him. "It might even be exciting. The risk of being caught."
Sirius smiled up at him. "Secretly you've just always been the worst Marauder. You're just better at hiding behind your good manners."
"Exactly," Remus grinned, taking his chance to kiss Sirius now he was looking up.
Sirius hummed and managed to focus on pleasure rather than his worries. After a while, he reached out for a tissue to remove the last traces of his crying, and then smiled back at his boyfriend. "I'll think about it," he said. "If we can do it. If I can stay away from you by day if it means that at least I can have you in the nights. It sounds better than staying away from you for a whole week or month or however long they will try to keep you from me."
Remus nodded. "You don't have to decide right away. Besides, I want to put your attention on something else now."
Sirius giggled and kissed him. "You have my full focus. I want to feel you everywhere."
Remus hummed and loosely wrapped his hand around his lover's cock. "Everywhere?" he teased.
"Yes," Sirius groaned, impatiently moving into his hand.
Remus grinned and kissed his neck. "It's really been too long."
"Ssh," Sirius said, closing his eyes and banning himself away from his distressing thoughts. It helped that Remus' lips found his and that his hand was increasing its pressure. "Lube," he moaned, making Remus giggle and his heart jump.
"You're so impatient," Remus said fondly, taking the bottle and pressing lube on his hand.
"I don't understand how you don't explode with all that patience and teasing and hmmmf do that again," Sirius muttered.
Remus laughed again, but didn't repeat the movement on Sirius' cock and pressed a slick finger between the cheeks of the other man's arse.
"More," Sirius begged.
"A moment," Remus said, preparing him tantalisingly slow.
"Now, Moony, please."
Remus licked his lips, his own patience running short as Sirius was begging. "Come on then."
He pulled back his fingers and applied more lube on his cock, then looked up at Sirius and nodded.
Sirius moaned as he let himself sink down on Remus' cock. "Moony," he whispered.
Remus pulled him down and kissed him deeply. "Can I move?"
"Please," Sirius nodded, then kissed him again as he rolled his hips and Remus thrust up.
When they sped up their rhythm, Remus started stroking his lover, and neither of them could make it last long as they were biting and sucking on each other's lips. As Sirius cried out, Remus caught him and followed with only a few thrusts, then lay still for a long while, just stroking Sirius' back.
"I love you," he mumbled after some time, partly to make Sirius move off him before he fell asleep.
Sirius hummed and nuzzled his neck, then rolled on his side and pulled Remus close. "Sleep well," he said, but what he actually meant was 'don't leave'.
"You too, love," Remus sighed happily, but he meant 'never'.
((My headcanon is that Remus' boss, M, is BBC's Mycroft Holmes. Though it also works with Dame Judi Dench's M of course.))