Once the two had gotten up from their dreams, they put their plans into action. Handing over their supposedly otherworldly objects to the Tails of their respective worlds and explaining the situation, the two foxes got to work, at least with a little more convincing. Knuckles' Tails had needed a bit more persuasion, but gave in after realizing that Sonic's flower crown did indeed have different properties.
It took a few days of solid effort due to fights with each Eggman delaying the process, but each Tails finally completed their machines; ones that would allow crossing over between worlds. During the dreams that Sonic and Knuckles shared in the meantime, it was decided that Knuckles would go to Sonic's world.
In Knuckles' world, Tails noticed a small flicker on his screen and smiled. "That's the signal! That's the signal from the other Tails!" he exclaimed excitedly. He turned to Knuckles, his tails swaying in excitement. "Alright, Knuckles, it's ready. Just stand on that platform over there and I'll beam you over. Also, don't forget that you can come back anytime you want, okay?"
"Okay!" Knuckles replied with a grin.
He got up on the platform, nearly bursting with excitement.
Tails gave him a thumb's up, then pulled a level on his machine. The platform below Knuckles glowed bright, and the echidna vanished.
Suddenly, he found himself in a completely different lab. Tails seemed to be standing in the exact same place, but his position was different and he wore a different outfit. Not that Knuckles would've taken much notice of it though; what was only a few meters in front of him was what caught his attention more.
Sonic stood there, eyes lit up with excitement as he gazed back at him. "Knuckles..." he muttered softly, a soft smile forming on his face.
All of a sudden, the hedgehog rushed towards him, intent on keeping his promise.
Knuckles ran towards him as well, feeling light as a feather. He scooped up Sonic in his arms, and kissed him right on the lips.
Sonic gripped Knuckles' shoulders excitedly, kissing back full-force; it'd been the absolute worst experience having to wait to kiss him like he'd been wanting to. Now though, the wait didn't matter because it was worth it. He cherished the kiss, along with the warmth and texture of Knuckles' fur, which he hadn't been able to feel before.
Knuckles felt a swarm of butterflies in his stomach as he sank into the kiss. He felt like he'd been waiting for an eternity; now, the moment was finally here. The warm feeling of Sonic's fur against him made it even better.
However, Sonic quickly broke up the moment as he remembered that there was someone else in the room with them. He slowly glanced over, seeing a shocked Tails standing not too far away, his face slightly red from embarrassment and the fur on his tails puffing out.
"R-right," Sonic muttered, his face turning red as well. He got down, then gestured to Knuckles. "Tails, this is Knuckles. Knuckles, Tails, oookay…" He quickly grabbed Knuckles' hand and escorted him out of the lab.
"Wow," Knuckles said as they stepped out into the city. "It looks even cooler in real life!"
Sonic smiled. "Yup! Always nice to feel the air on your face too."
Like an excited child, Sonic tugged harder on Knuckles' hand and walked a little faster. "Now c'mon! My house is this way! I promised you a key, right?" he reminded him.
"Oh, right!" Knuckles grinned. He couldn't wait to see Sonic's house for real.
Sonic took Knuckles to his house, then unlocked the door and walked inside. He grabbed a key under a potted plant, then tossed it to Knuckles. "There ya go!"
"Thanks!" Knuckles replied, tucking the key into his hammerspace.
Sonic smiled. "Though... there's one other thing..." he said, gesturing for Knuckles to get down to his level.
Knuckles bent down. "What is it?"
Sonic smiled, then leaned close, whispering a small "I love you" to Knuckles. The only difference was that it was in the ancient echidna language, with the accent perfect and every syllable pronounced just like it should've been.
Knuckles' jaw almost dropped.
"Where did you learn that?" he asked, amazed.
Sonic smiled sheepishly, blushing. "I knew I'd be meeting you soon, so I've been takin' lessons from the other Knuckles," he explained.
"Ohhhhh. Cool!" Knuckles smiled. "I'm really impressed!"
"Good!" Sonic exclaimed. "I just knew I wanted to be prepared for you when ya got here." He placed his hands on his hips proudly. "I also stocked the fridge with grapes."
Knuckles' eyes lit up. "Really? Wow, you thought of everything!"
"Of course! Gotta do my best for ya, right?" Sonic asked with a grin. He sat down on his beanbag chair, then offered Knuckles a seat next to him, echoing back to their very first dream together.
Knuckles sat down next to him.
"Oooh, it's even more comfortable in real life!" he mused. He blushed when he felt the warmth of Sonic's body next to his; another reason as to why it was even better than the dream.
Sonic laughed. "It should be!"
He wrapped an arm around Knuckles' waist, then pulled himself closer, snuggling into his side.
Knuckles also put an arm around Sonic, enjoying their first real cuddle.
"...Y'know, that other you was kinda right," Sonic admitted with a small sigh. "I'm pretty reckless and impulsive. Tails almost got turned into a robot and I nearly got my friends killed a few times." He tightened his grip on Knuckles. "I wouldn't wanna put you in danger."
"Don't worry about me," Knuckles assured him. "I've been in danger plenty of times; I can take care of myself."
"Yeah, I know," Sonic said softly. His smile slowly returned. "That's good, 'cause I'm like some sorta danger magnet."
Knuckles chuckled. "Sounds like a normal day for me and my friends."
"Oh yeah? I guess you're a little safer here then," Sonic said. "Eggman waits most of the time to attack, heh. Once or twice a week, tops."
"Really?" Knuckles was surprised by this. "The Eggman in my world attacks pretty much every day!"
"Yeaaaah... I guess mine's a little more, "blarg, I'm gonna make this huge plan that'll take weeks to put into action and still get beaten by a single blue hedgehog" than yours," Sonic said with an amused smirk.
Knuckles chuckled. "Yeah, my Eggman tries to destroy us all the time, but always fails. I think it's more like a game now, heh."
Sonic giggled. "Sounds familiar."
He crawled onto Knuckles, then gave him a quick kiss. "Now c'mon. We need to make up for all those times in our dreams where we could've been kissin'."
Knuckles grinned. "Sounds good to me!"
And so they did, never leaving each other's side for the rest of the day, too focused on catching up on the time they wanted to spend together.