Obligatory disclaimer: Merlin and all associated creative properties belong to BBC. I don't claim any said property as my own, and I make no monetary profit from this fan-made story. All creative property not associated with said channel belong to me, and their use is limited to my express permission. Thank you.
Not edited, please point out the mistakes for me to fix.
Arthur retrieved the spare key from the fire extinguisher's cabinet which was located next to Morgana's flat.
His half-sister had been nagging him for days to assemble her newly purchased bookshelves.
Naturally, when she first asked, his answer was an immediate no.
Morgana had like hundreds and hundred of books which meant the bookshelves she got would most likely occupy an entire wall. Which meant, it would take him a day to set them up because the old one needed to be removed first.
A day, he had no intention of wasting.
But Morgana, being her cunning self, threatened to reveal to Gwen, her flatmate, that he fancied.
Something Arthur was still not ready to announce. So putting up some shelves it was.
Although, he still had no idea how Morgana found out.
He chose not to tell Morgana what he was going to do because he wanted it to be a surprise. Perhaps, it would make her stop teasing him about not telling Gwen how he truly felt about her.
He really hoped she'd stop.
Arthur unlocked the door and pushed open.
That was when he heard it.
A grinding noise coming from Morgana's bedroom.
Arthur stood still.
He was certain Morgana wouldn't be home at that moment. She had plans to spend the day with her nephew, Mordred.
It must be a burglar. In plain daylight.
The audacity! Arthur thought.
The blond hair man decided to leave the front door open. He pick-pocketed the key and retrieved his phone.
He had just pressed two nines when a groan reached his ears followed by: "Merlin."
"Sorry." Followed soon after.
What the hell?
That was Morgana's voice. Evidently, Merlin was with her as well.
What were they doing there exactly?
Arthur locked his phone and put it on the entryway table. He approached the source of the noise.
"I thought you said you've done this before." Morgana sounded breathless.
"I have..." Merlin protested with a feeble voice that trailed off in a moan.
Oh my God! Arthur's eyes widened. Were they... doing it. His hands shut up into clenched fists.
Did Morgana lie to him about today just so she could have her way with Merlin?
How long had this been going on?
"Don't touch that...that hurts..." Morgana released another sigh and Arthur's heart skipped a beat, "How many times have you done this before?"
"Two, maybe three times." Merlin answered. He sounded exasperated, "But, I know the basics."
"Clearly you don't..." Arthur felt his stomach churn. "...you're doing it wrong."
That didn't sound right. Merlin's last relationship had lasted for 2 years before he broke it off. It shouldn't have lasted that long if he didn't know how to do it correctly. Right?
Well, either that, or his sister had a very strange kinky side to her that Merlin obviously couldn't keep up with.
What were they doing there?
Arthur shook his head trying to shove the thoughts and the offensive images his mind had conjured up out of his head. He should probably leave, he was about to throw up inside his mouth.
"Trust me, I know exactly what I'm doing. Mostly."
She puffed, not believing his claim."Arthur is better at this than you."
It was at that particular moment that Arthur stopped breathing, shocked by what he just heard and for a second there, it was like his soul had left his body.
Did he hear that right? Perhaps he misheard it?
Why would she say that?
No really? Why would she insert his name with those words in that order?
Were they role-playing as brother and sister?
What was wrong with them?
Arthur released the breath he'd been holding and pondered his next chain of actions. Escape this horrendous incident he'd walked in on and pretend he'd never listened to this conversation. Or, escape this horrendous incident he'd walked in on and never speak to Merlin and Morgana ever again.
He was really leaning towards the second choice.
"You're going to make me regret offering to put up these bookshelves."
"I'm already regretting accepting your offer."
"It's not my fault your wall is not straight."
"My wall is perfectly straight, Merlin. It's your carpentry skills that are complete rubbish."
Wait a minute, rewind that a bit.
Bookshelves? Wall? Carpentry skills?
His brows squished together in a confused frown.
Merlin had no carpentry skills. Arthur was sure of it.
Suddenly his legs worked on their own accord and Arthur found himself standing in front of Morgana's door watching a scene that could only be described as comical.
It seemed like Morgana had chosen an intertwining design for the shelves that she had bought. And one of them had come loose after they started putting the books on which impacted the whole structure. So Merlin and Morgana were each grabbing a different shelf trying to keep it from falling to the ground.
Unintentionally, Arthur snickered and it startled the two occupants.
Merlin tore his gaze from Morgana, his eyes landed at him. "Arthur?"
Morgana, who had her back to him, reacted badly and she jumped releasing the rack she was supporting.
She whirled around and glared at him. "What the hell, Arthur? You scared me."
"You two almost gave me a heart attack. I guess we're even."
"What?" Morgana's expression shifted into one of confusion. "Why?"
Arthur just smiled to himself. He wasn't going to tell them that he thought they were having sex. That was something that he was going to take with him to his grave. He waved his hand dismissively. "I thought someone broke in. A thief." He looked at the scattered books on the ground. "I have the toolbox by the door. I'll just go grab it and we can fix this mess in no time."
Arthur took two steps backwards when he remembered something, "Hey, Morgana. I thought you're going to Morgause today."
"Ah," Morgana hummed, she glanced at Merlin for a second before she answered Arthur's question. "Mordred has a football practice today... Morgause forgot about it. I'm going to see him tomorrow."
Arthur noticed the nervous look they shared at his question but he didn't think much of it. He left them and went to retrieve the abandoned box.
"Fuck!" Merlin expressed when Arthur was out of earshot. "If he had come an hour early, he would have found us in bed."
"Yeah." Morgana covered her face with her hands. "Could you imagine what he would have done?"
"Kill us?" Merlin shrugged his shoulder.
"No,he would have killed you."
A/N: A response to a prompt from tumblr. I hope you like it.