Ratchet has been missing his sparkmate, remembering what he did that separated the two for stellar cycles. Even with his aching spark, he goes on patrol and picks up an Energon signal. He finally found (Y/D), and the two celebrate reuniting in an unusual way.
Warning: Sexual content

Ratchet's P.O.V.
It's been stellar cycles since I saw my sparkmate (Y/D). I've lost track of how long we've been apart. Only Prime knows what I did. He tries to assure me it was the right thing to do. (Y/N) might have died in battle, but I don't know if she's alive. What if I could have protected her better than putting her in an escape pod?

Flashback
The cons are trying to attack the Autobot capital; Prime leaves the team defending the launchpad as I assist in making sure femmes and sparklinga escape while debating on forcing (Y/D) to flee on the last pod. She's a fighter, but she'd be safer away from the est; I wouldn't have to worry about keeping her safe.
"Let's go!" (Y/D) yells as the last few femmes run into the last pod.
I quickly put her in the pod and launch it.
"RATCHET, WHAT ARE YOU DOING?!" She yells as the pod prepares for launch.
"PROTECTING YOU!" I yell before the pod blasts into space.
Goodbye, my love, we'll be together someday.
End of flashback

Bumblebee's P.O.V.
I wasn't prepared to hear crying as I open the door to Ratchet's room.
"I'm sorry, (Y/N)!" Ratchet cries.
I'm glad this isn't urgent cause he needs time alone. I slowly close the door and walk away.

"I know what troubles him; it is best to leave Ratchet alone," Prime tells me.
What has the grumpy medic bawling?

The next day

Ratchet's P.O.V.
I do not like this feeling in my spark as I online. Thinking about (Y/D) — and how it seems we'll never be together again — brought on this feeling. I want to stay in my room, but it's my turn to patrol around Jasper. Perhaps This is better as I'll be away from everyone.
"Are you sure you're well enough for a patrol?" Prime asks.
I hate how he knows (Y/D) has been on my processor. I tell him I'll be fine. He tells me to take all the time I need.

After driving around the outskirts of town, I sit on a hill far from the road, watching the sunset, hoping to distract myself from the pain in my spark. Twenty minutes pass before my scanner alerts me about an Energon signal, but I can't identify if it's a con or an Autobot that just came to Earth.

The signal takes me ten miles from my location; to an open flat area. I transform twenty feet from the transformer. I hear them cursing in Cybertronian as they sit on the ground. A cybertronian femme...it can't be...

(Y/N)'s P.O.V.
The peds stop a few feet beside me. I stand up and shine a light on the figure with my servo on my gun. I must be injured as I'm seeing my sparkmate, still as handsome as ever, even with old age.
"R-Ratchet?"
I feel awkward talking to an illusion, but my spark pulses, which must mean...
"I'm here, (Y/D)," Ratchet says.
Without thinking, my legs run to him, and I hug him. I feel Ratchet's arms around me.
He's real, he's here; I found my sparkmate at last.
It's not long before we are both crying.

We sit on the ground as we continue to hug and cry.
"H-How did you get her?" Ratchet asks.
"I found a faint Autobot signal, leading me to Earth, but it got jammed when I got here."
We end up talking — catching up on centuries being apart.

"...I thought you...moved on..."
"What? No, I couldn't; I love you. Maybe this will convince you."
I pull him closer for a kiss how I've missed kissing these dermas. This loving kiss turns passionate as we stand up, and I jump onto Ratchet, wrapping my legs around his waist. Without breaking the kiss, Ratchet walks a little bit, the flat land turning into a cave.
It's not like anyone could see us out there, Ratchet.

He pushes my body against the wall.
"Primus, I've missed kissing those dermas," Ratchet chirps as I stand on my peds
"We have to tell Prime I'm back," I tell him.
"We'll surprise him and the others later, but for now, I need to keep you to myself."
I jump onto Ratchet and kiss him, resulting in both of us on the ground.
"Sorry," I apologize.
I lay on Ratchet for a few minutes before feeling like we should frag. Dure, we just reunited, and it might seem odd, but Ratchet is also my sparkmate.

Laying on Ratchet feels great; much better than the famn space pod I've been in. It was all I could get on the planet I and several femmes lived on. Thankfully, the native species were friendly and helpful.
"Are we sleeping here tonight?" Ratchet asks.
"I'm sure we'll be tired from our fun," I smile.
"W-what fu—?"
I interrupt him by sucking on his neck cables resulting in groaning from Ratchet.
"Good idea," he smiles before rolling over, resulting in me on the ground, but Ratchet sute on his knees, rubbing our panels together. The sound of our bodies making contact echoing un the cave. This doesn't last long before Ratchet renoves the plating and sticks a digit in my valve. I mosn as he gives me a valve massage; visualizing his spike in there rather than a digit. Ratchet continues until I'm ready down there before removing his panel revealing a spike that's ready as it sticks out.

Ratchet's P.O.V.
I didn't think (Y/D) would want to do this so soon after reuniting. It's been so long; I'm going slow for now. Feeling (Y/D)'s valve wet and ready, I slowly move in; letting (Y/D) adjust before moving slowly and kissing her
"So naughty," I tease.
It's not long before (Y/D) wants me to increase speed. Hearing her as I increase speed is music to my audio receptors.
This continues for a few minutes before I pull out and lay next to (Y/N).
"I missed this," she pants.
"Just the fragging?" I tease.
"No, seeing my sexy doctor of a sparkmate. I think I still need to familiarize myself with your spike."
I look at (U/N), seeing she's serious and wants another round. I do want my sparkmate wants until she's tired; I hold her close to me as we recharge.