Author's Notes: Rated T, mostly for profanity. This is Morgan/Reid established relationship.

***I do not own Criminal Minds or its associated characters.***

The Patience of Dr. Reid

For all of his genius, Spencer Reid could be truly oblivious sometimes. It was their six month anniversary, and Derek had painstakingly planned and prepared a celebratory dinner. The only hitch in his plans: The second guest of honor had failed to show. Of course, it wasn't entirely his fault. It had been a surprise dinner, after all. And where was Spencer while Derek paced the floors of his house for hours, constantly making calls and checking for new messages?

"Seriously, Derek, how often will I get the chance to meet the Edward Witten in person? You know, he actually has a great sense of humor…"

"Spencer."

"I asked him about his work on Superstring theory and his opinion on its merits as opposed to Bosonic string theory and…"

"Spencer."

"…what he thought about Polchinski's paradox, and he actually said-"

"Reid!"

"Wha- huh?" He blinked confusedly, his near-manically flailing arms suspended in mid-motion.

"A book signing, Spencer?" Derek was incredulous. "You ignored our six month anniversary to go to a book signing?"

"You usually have defense classes on Wednesday nights, and I couldn't exactly leave my phone on during the reading and subsequent Q&A, and- Wait… anniversary?" he squeaked, only now really comprehending his folly.

Derek shook his head and laughed humorlessly.

"Unbelievable. You can't honestly tell me… Spencer, how long have we been together?"

"6 months, 1 day, 2 hours, 14 minutes."

"Exactly."

"Exactly what? I don't understand."

Derek fought hard to hold on to his indignation, despite the endearingly baffled look on his lover's face.

"You didn't forget, Spencer, because you can't forget. Which means that you chose not to acknowledge this date. And I gotta tell you, Pretty Boy, to think that celebrating our anniversary comes second to a book signing? Well, that hurts."

Spencer stood gaping and silent, lips beginning to form words several times before finally pressing into a thin line. It would have been amusing at any other time.

"Derek, I-" He ran shaky fingers through his unruly curls, shutting his eyes in frustration. Derek could practically smell the synapses burning out as thoughts tried and failed to connect. Spencer Reid speechless was a rare sight. When it became clear to both men that no better thought would present itself, he offered the only reply that he could.

"I'm sorry."

And that should have been the end. Derek should have shouted down that tiny, treacherous voice nagging at the back of his mind that told him to be angry, to be offended, to be wary of the implications of this event. He should have reasoned with that part of himself that rejected cold logic for raw emotion and forgiven him immediately as a matter of course. It's not like Spencer hadn't apologized, right? But as had happened so many times in his life, Derek found himself losing that internal argument. The voice was louder than logic. It was blaring. It was persistent. It had a point…

Spencer didn't really sound all that sorry, did he? He never even claimed to forget the significance of the date. Here he was, a genius with an IQ of 187, an eidetic memory, and no less than five degrees (including three fucking doctorates) and the best he could do was 'I'm sorry'. The voice was nearly growling now- biting and sarcastic, cruel and indifferent to any attempt at pacification. It questioned loyalties, hurled accusations, snarled like a wounded animal locked in a cage with its tormentor.

It was the resounding crack that reverberated throughout the silent room that drew Derek out of his own internal conflict. He hadn't even felt the pain. Now, as he looked at Spencer, noticing the odd way that he stared down at his own hand as if it were something foreign to him, the voice was quiet.

"Spencer?"

He took one step toward the younger man, frowning when he in turn took two steps back. Large brown eyes lifted to meet his own, and Derek saw the one emotion he had hoped to never see in Reid's eyes: Fear. His body trembled with the effort of suppressing the tears that fell in increasing frequency over flushed cheeks. He dropped his gaze back to his hand and seemed to quake harder for a brief moment, and Derek wondered if Spencer was more afraid of his own violent action or the possible reaction of his much stronger lover.

There were few things that truly angered Spencer Reid and even fewer that could drive him to strike another human being in anything other than self-defense. The reserved man had obviously been driven to that breaking point. 'But by what?' Derek wondered, and as if in answer to this musing, he heard that whisper of disquiet building to a litany of accusation once again.

What right did the kid have to look so damn broken? He was the one who had been stood up. Whose feelings had been ignored and then dismissed with a half-hearted 'apology'. The one who had been slapped for simply telling the truth.

Who the hell slaps a grown man, anyway?

Derek's fists clenched and unclenched in an effort to rein in the overwhelming flux of emotions that threatened to engulf him. His breaths eventually grew calm, and his heart rate slowed. As the last echoes of dissent died out, he realized something: That voice had sounded a lot like his own. And he knew that he had spoken those thoughts aloud. Those bitter, spiteful words that had consumed his mind like fire had not been contained at all.

He had accused Spencer of not caring about their relationship, of being too socially inept to understand how a relationship works. But worst of all, he had called Spencer a liar. He had suggested that there was no book signing and that he'd not answered his phone for entirely different reasons. That had been the last straw. The seemingly infinite patience of Dr. Reid was exhausted, and he'd lashed out. Derek didn't blame him. He wanted to hit himself at this point. Looking now at the pained face of his lover, eyes tear-filled and staring directly into his own, Derek felt any and all traces of anger dissipate in an instant.

"Spencer," he nearly whispered.

"You promised, Derek."

His voice was calm and deathly quiet, reminding Derek of being caught in the eye of a massive storm.

"We promised that no matter what happens down the line, whether this thing between us lasts for ten years or ten days, that we would never forget what brought us together in the first place- friendship and trust. Trust, Derek!"

The older man actually flinched as the quiet admonishments were interjected by the shout.

"I trust you. I have trusted you with my life for so long that it was almost too easy to trust you with my body, with my mind, with my heart."

"Spence, please."

"No! I have listened to you rant and rave for fifteen minutes, Derek Morgan. It is my turn to speak now."

Derek nodded mutely like a thoroughly chastised child.

"You drag me out to some strobe light illuminated hell- and by the way, I think that the music in Hell would probably be more tasteful than the auditory pornography that I'm subjected to- every other week, and I have never shown any distrust in you. Not when you disappear for twenty minutes at a time. Not when I see you surrounded by some of the most morally questionable women on the planet, hanging off of you like the stage prop at their day jobs. But do I say anything? No. Because it's something that you feel like you need. Because I don't begrudge you that outlet. Because at the end of the night, after all of the innuendo and all of the unnecessary physical contact, I know that you'll offer your apologies, excuse yourself, and walk out that door with me."

Reid took a moment to catch his breath, still refusing to break eye contact with the man before him. Derek, for all his impatience, knew better than to assume that Spencer had finished. That had been the eye of the storm. This was far from over, and all he could do now was anchor himself to something sturdy and hope to survive.

"So, now I'm a liar? And an unfaithful one at that."

"Baby, I never said you were unfaithful."

"No. You just implied. What else could you have possibly meant by 'You never turn off your phone. Even if it was on vibrate during your oh-so-damn-important book signing, you would've checked your messages to make sure we weren't being called in. You're lying, Reid. The last time you lied-'" Here, the genius halted his verbatim account of Morgan's tirade, as that had been the moment that the irate man had been silenced with a sound slap. Derek could see the comprehension dawning in those luminous brown orbs, and he braced himself once again.

"Wow. I am so…, so very stupid." The words were soft and tinged with self-scorn. "You didn't think that I was cheating on you, did you?" he asked rhetorically. "Why would you have to worry about that? 'The last time you lied and didn't answer your phone was in New Orleans.' That's what you were going to say, isn't it?"

Derek's closed eyes and slowly exhaled breath was all the answer he needed. A sound somewhere between a choked sob and a growl caught in Spencer's throat. Derek expected more shouting. He prepared himself to dodge the nearest object that could be flung at his head. He reminded himself that, no matter what, he could not hit Spencer back as he braced himself for the conflict. Having grown up in a household with three females, he was well acquainted with hysterics. It was one of the reasons for his long-time One Date Rule. In his experience, all relationships eventually ended in hysterics.

What he hadn't expected was the cool indifference that Spencer suddenly wrapped around himself like a cloak. He hadn't expected a now dry-eyed Spencer Reid to give that trademark lopsided grin with no hint of malice as he slung his messenger bag over his shoulder and said with that little half-wave "Thanks for having me over, Morgan. I'll see you at work" before casually walking out the front door. He didn't expect to still be standing there a full three minutes after the door had closed, feeling more confusion than he'd felt in years compressed into the space of a few minutes.

"What the hell just happened?" he asked aloud.

But of course, there was no answer.

Comments and constructive criticisms are most welcome.