A/N: Firstly, I pictured this in my mind as a Muggle!AU, and so it is.

Secondly, as much as I love writing Blackinnon as a couple, I thoroughly enjoy writing them as best friends. I had so much fun writing this once I got the idea properly formed. I hope you enjoy it as much as I did!

Prompt: (story title) Home Alone

Home Alone

A loud knock on her front door brought Marlene back to the present. She'd been thinking about her stupid ex-boyfriend again, wondering if she'd made the right choice. Will I ever really know? Maybe I should call him back, tell him I've reconsidered...

The knock came again, more insistent this time. She pushed her untouched food to the middle of the table and stood from her seat. "I'm coming, stop already," she called as she reached the entrance. Irritated at being ripped from her solitude, she pulled the door open roughly. "What are you doing here?" The words were out of her mouth before she could stop them, sounding much harsher than she'd intended.

Sirius stared back at her, one eyebrow raised. "Why hello to you too, McKinnon. Just thought I'd come find out why you and what's-his-name aren't at my place for the New Year's Eve party." He looked past her shoulder into the house. "Where is he, anyway? I figured he'd be here."

"I don't really care where he is," she spat. "I decided I didn't want to move in with him after only knowing him for four months, so he decided to dump me." She glared down at her feet, blinking back tears. She may have only known him for a short time, but she'd enjoyed being with him. Being thrown away so casually stung badly.

"Well, if it makes you feel any better, I never liked the little jerk anyway," Sirius said after a moment's silence. "He didn't suit you."

"Oh really?" It was Marlene's turn to raise an eyebrow, her heartbreak forgotten. "And just who would suit me?"

Sirius leaned casually against the door frame. "I was thinking someone stunningly handsome, with black hair, grey eyes, and the ability to charm his way out of trouble. Oh, and a badass motorbike."

Marlene laughed and punched him playfully on the arm. "If this is your way of asking me on a date, Sirius, then my answer is no."

"I'll get that date one of these days, I promise you." He straightened and stuffed his hands into his coat pockets. "So, do you want to mope around here all night feeling sorry for your beautiful, single self -"

"Sirius," Marlene said warningly.

"-Or do you want to come hang out at my place with the usual group? You know how much fun we have."

The pleading look in his eyes left her with no choice. "Oh fine. But no trying to kiss me at midnight." She pointed a finger sternly at him.

"I wouldn't dream of it." He smiled mischievously. "Dress warm, I drove the motorbike over."

Marlene shook her head as she pulled on her warmest boots, sitting down to lace them. "Why would you have that thing out on December 31st? It's not even warm enough for it."

"I feel bad, leaving it locked up in the garage all winter. It gets lonely."

She stifled a laugh as she grabbed her coat out of the closet and shrugged it on over her sweater. She took her keys from their hook behind the door and pocketed them, stepped out into the cool night air, and locked the door behind her. "Maybe you should be dating that thing. You seem to love it so much."

"Oh, ha ha, very funny." He stuck his tongue out at her as he got onto the bike. "Be nice or I'll make you walk all the way to my place."

"Not very threatening when I could just go back in the house." She pulled on the gloves and hat she always kept in her coat pocket and got on behind him, wrapping her arms around him as she did every time she rode with him. "Thanks, by the way," she added soberly. "For not letting me sit at home alone tonight."

"Anything for you, Mar." He started the bike and the engine roared to life.

Marlene smiled as they sped through the night, hugging Sirius tightly. Forget stupid exes. As long as I have him, my craziest, most loyal friend in the whole world, I don't have anything to be unhappy about.