Spencer sat up in bed, his arms crossed in front of him, while Derek was in the shower. As always, he was spending his quiet time thinking to himself. Though the time periods were never long, he enjoyed when he had little moments away from Derek to give him time to clear his head. Considering everything that had happened with Chester Hardwick while he was visiting him with Hotch, he was ready to erase it all from his brain the best he could and spend the rest of his night not worrying about anything.

When Derek walked out of the bathroom, he saw Spencer deep in thought and smiled to himself. "I can hear you thinking over here, kid," he said, pulling on his pajama pants and walking over to the bed, sitting beside him and running his hand through Spencer's hair.

He uncrossed his arms. "I don't know how many times I have to tell you, Derek, it's impossible to actually hear somebody's thought process. I don't know why you insist on constantly using that saying, because it makes absolutely no sense."

Derek smirked, kissing Spencer softly. It was always the one way to stop Spencer mid-ramble, and he knew that it was for the best, because Spencer would instantly lose his train of thought to return the kiss. When Spencer pulled back, he looked him in the eyes. "It's just an expression."

"So, it's like that tree song?" he asked, facing him.

Derek raised an eyebrow. "What tree song?"

"When we were sitting in the bullpen after you finished the Galen case, and Hotch and I came back from dealing with Chester Hardwick in Connecticut? Kevin Lynch was waiting in Rossi's office to talk to him about Penelope. You were concerned about her well-being, as any friend would be, and JJ started singing this song that I've never heard before, and I don't quite understand it."

"What song are you talking about?"

Spencer screwed up his face, recalling it. "Garcia and Kevin, sitting in a tree."

Derek laughed to himself. "That's it?"

"Well, yeah, that's all JJ got out before she walked away, and you asked her if she was serious. I don't get it."

Derek bit his lip to hold back his smile. "You don't?"

"No! And Emily said nothing scandalous was ever going to happen in the BAU, and I told her I didn't understand what it meant. She asked me if I heard JJ, which of course I did, but I didn't get the meaning behind it. She went to describe it to me, but she just stopped short. It's been bothering me ever since."

"Think back to your days on the playground. Did you ever hear a song at least somewhat similar to that?"

He chewed on his cheek, thinking. "My playground memories aren't altogether pleasant. I spent most of my time on the playground in elementary school hiding from the older kids. The songs they came up with weren't that nice, so I did my best to repress them."

"Okay, let's change the subject. You've never had a crush on anyone?"

"Well, yeah, I had crushes, but I never acted on them, considering my age and appearance at the time. I was considerably shorter, so I never told any of my crushes, nor did I sing songs about them, which is apparently the appropriate thing to do in the situation, from what I saw tonight. Even if we are adults, the best response is to sing a childish song."

Derek shook his head. "Spencer, do you want to know what the song means?"

"Yes, please." He tucked his legs underneath himself. "I'm ready to learn."

He smirked."This is a welcomed change."

"Derek-"

"Well, Pretty Boy, let me put it into terms you'd understand."

He shifted, resting his elbow on his knee and resting his chin in his hand. "…I'm listening."

"Let's just change the words. 'Derek and Spencer, sitting in a tree, f-u-c-k-i-n-g-"

"But why would we be doing that in a tree?"

"…Excuse me?"

"Well, we've done it in odd places, I'll admit. We've used the kitchen counter, and sanitized it afterward, as well as a desk, which was definitely its own adventure, but in a tree? I think that would be rather unpleasant, don't you? Not to mention it's extremely dangerous, considering we don't know how sturdy the tree would be, let alone if it would be able to hold both of our weights during moments of pleasure-"

Derek sighed, thinking. "It's not about the subject matter, it's about what's being spelled out. In a tree is just for the sense of rhyming the 'g' at the end of the spelled word. Do you understand?"

Spencer looked at him. "So nobody was ever sitting in a tree?"

"Not that I'm aware of, no."

He chewed on his cheek. "So Garcia and Kevin sitting in a tree. That's just another way to say that they're kissing? What's wrong with them kissing? They're grown, consenting adults, I fail to see the problem with it-"

Derek put a finger to his lips. "Shh."

"But Derek-"

He shook his head. "It's not about them kissing."

"Then what-" he paused, thinking. He finally caught on and gasped. "Garcia is dating Kevin Lynch?"

"There's my genius."

"But… they're dating? And she didn't tell us? Over the past year and a half, we've had to divulge every single detail of our relationship, whether we wanted to share it or not. We had to tell her about our date nights and very personal, intimate things that really shouldn't be shared with co-workers, but I knew she'd find out if we didn't tell her. How is it fair that we've told her everything and we had to find out from a rhyme?"

He shrugged. "I guess she's a private person."

"And I'm not? Derek, if it weren't for Garcia, our relationship would be very much private right now, and nobody on the team would know until I was ready for them to find out. Not to mention that-"

Derek shook his head, once again capturing Spencer's lips with his. Spencer smiled to himself, forgetting about his rant as he wrapped an arm around Derek's neck, returning the kiss and pulling him in.

Derek pulled back, catching his breath and smiling. "Is that better?"

Spencer nodded slightly. "Though, I have to admit, I think we should be sitting in a tree."

"Is that so?"

"Mhm."

Derek smirked. "Let me just take Clooney for a walk, and we can do whatever you want in a tree."

"That sounds perfect."

"And Pretty Boy?" Derek started, getting off the bed.

"Hm?"

"I'd be glad to educate you on anything any day."

Author's Note: Just a one-shot idea based on the episode 'Damaged', when Spencer didn't understand the song JJ was singing about Garcia and Kevin.