Fair warning: the smut has arrived. Also, sadism and masochism lurk here.

Greg was sitting on his sofa, eating Chinese take away, and pondering whether or not he could really go to sleep when his mobile rang. The number was blocked.

"Hello?" He answered skeptically. It was almost 22:00 on a Tuesday evening. Who would be calling at this hour?

"This is my private mobile," Sherlock's voice dripped out of the speaker silkily. "I don't use it for the work. Only for drugs. I think I have the numbers of half the major dealers in the city stored on here."

Greg let out a small groan. "Are you daring me to confiscate that phone from you?"

"I'm bored," Sherlock paused, "perhaps I'd even give you a hint to where I usually hide this particular mobile if you get over here quickly. But this is a one night only offer. If you come looking for it tomorrow, I promise you'll never find it."

"So you want me to come and search your flat for a phone that would put me in contact will all of your dealers… right now?" Greg sighed.

"It's been at least a month since you last did a drugs bust. I'm starting to feel a bit neglected, Lestrade."

"I thought you hated the drugs busts," Greg snorted.

"Come now. I know you're dull—but I thought this would be obvious, even to you. Shall I give you a moment to catch up?"

"What are you talking about?"

"I'm giving you an excuse to come by my flat in the middle of the night. Think over the implications."

Oh. Oh dear.

Deep breaths, Lestrade. You're better than this. He's having it on. Because who the fuck does this? Really. It's insane.

"Sherlock, I've already told you," Greg began steadily, "this is inappropriate. I'm pretty much your liaison officer. This is a work relationship. Nothing else. If it became anything else, I could lose my job."

"I didn't ask for excuses," he could practically hear Sherlock rolling his eyes, "they're excruciatingly predictable. And since when have you cared about bending the rules for me?"

"This is different."

"No it's not. What are you so afraid of? It's not like I'd tell anyone."

Greg's heart was thumping in his throat. He was sweating.

"I don't care. It's still a bad idea. Why is my not wanting to shag you such a difficult concept to grasp?"

"Because I know you're lying," Sherlock laughed. "I bet you're thinking about it right now. My delicate wrists, cuffed behind by back. Would you press me up against a wall like you did the first time I showed up high to a crime scene? Or would you tangle your fingers in my hair and shove me down onto my knees?" Sherlock's voice had changed. Gotten deeper, sunken into a sort of sultry purr.

Greg's breath caught. Well weren't those some lovely little mental images? Wait, NO. He shouldn't be thinking about that. Sherlock pressed flat against a brick wall, struggling to get free... or on his knees choking around Greg's cock... shit. Greg tried to shake himself mentally, but it didn't really work. Because the mobile speaker in Greg's ear was still filled with Sherlock's voice, and it was still saying wonderfully filthy things.

"You know I still think about it," Sherlock was talking quietly, so Greg had to strain to listen. So he was forced to pay attention. "Sometimes, when I touch myself, I cuff one of my arms to the bed, and pretend it's your fingers inside me."

Goddamn it. Greg's cock was rapidly filling out. This was not good. He should hang up. But then there was the sound of a zipper being pulled down, and Sherlock let out a tiny moan.

"I think about the first time we met and how you tackled me, and sat on top of me, and kept me pinned down. I think about how I squirmed and writhed, and struggled, and how you didn't let me up. And really, it's a lot more fun to imagine that we're both naked, and you're sliding into me while holding me down. Because I bet you wouldn't be gentle with me. And I'd love it."

Shit. Fuck. This was not happening. But it was. Sherlock was panting slightly. Was he actually wanking or acting? With Sherlock, it could be either. And somehow, that fact that he couldn't tell which it was sent a strange prickling arousal through Greg's body.

"I've already come once tonight. I fucked myself to completion on one of my larger dildos. Most of the time, I can orgasm through prostate stimulation alone. Would you like to fuck the come out of me, Lestrade? I think we'd both enjoy it."

His voice. It was like melted chocolate, and whiskey, and cigarettes, and pure sex—and it was making Greg ache in a lot of ways he really shouldn't.

"You have large hands," Sherlock had gone a bit breathy. "I bet they'd leave wonderful, dark, purple bruises around my neck if you choked me until I went limp underneath you."

Greg blinked and realized he'd been palming his erection unconsciously. He cursed under his breath, and clenched his hand into a fist.

"You could leave finger-shaped bruises around my hips as well. I'd wear my belt a notch too tight for the next few days, so it pressed against them and made the marks twinge every time I moved."

Oh fucking hell. Greg bit his lip to keep from saying—I bet you would, you slut, and I'd get hard every time you winced because of the marks I left.

Instead, he took a deep breath. "I'm hanging up now."

"Just when it was getting fun?" Sherlock chuckled darkly.

"Good night, Sherlock," he said curtly.

"Goodnight, Detective Inspector."

Oh don't worry. Things are going to get so much MORE fun. See you Tuesday!