Mirage returns from his mission and waits for (Y/N) to get out of surgery. He promises her he'll never leave her. He quickly makes plans for her birthday.

Optimus Prime's P.O.V.
(Y/N) is scared and needs Mirage here. I hope he'll get here before she's out of surgery. I wait in the hallway for Mirage to return. It's quiet for two hours. I don't know how much longer (Y/N) will be in surgery, but I hope Mirage gets back soon.
"OUT OF MY WAY!" I hear Mirage.
Just holoform pushing soldiers out of the way.
"Mirage, stop!" I yell.
Ironhide's holoform is close and rushes to stop Mirage.
"You can't even protect one human, can you, Lennox?!" Mirage rages.
"You know the risk involved being in the military. I am not telling (Y/N) she can't do a mission because you can't go with her," I explain, "she'll be ok, let him go, Ironhide."

Mirage walks down the hall, stopping by the medbay, and sits on the floor across the hall. I talk to him about what he could do for (Y/N)'s birthday. It's too late to plan a party with the others, but there are still things he can do.

Four hours pass before Ratchet walks out of the room.

"Surgery went well," he says, "with physical therapy, (Y/N) should be back on duty in four months."
"At least now you have an assistant with your cases, Mirage," Jolt adds.

Mirage's P.O.V.
I'm able to sit by the bed, waiting for (Y/N) to wake up. Her right arm is in cast in a sling. She does have a wrap for her ribs, but Ratchet says that's not staying on for long. She's on strong pain medication for now.
I don't have to wait long for (Y/N) to wake up.
"Mirage?" She asks tiredly.
"I'm here," I kiss her and take her hand.
(Y/N) tears up as Ratchet explains her injuries and the recovery process.
"Babe, it's ok; I will help you get through this," I assure her, "can I stay here until she's released?"
"Fine, but no fragging!"
"Seriously? Why would you have that idea?"
"I mean it! Not only because I don't want to hear you two doing it, but she can't until she's fully recovered!"
He leaves the room and goes to his office.
"My birthday is ruined," (Y/N) sulks.
"Not really, I have another idea for tomorrow, and when you've recovered, I have another surprise that I know you won't be able to resist."
(Y/N) smiles, probably trying to figure out what the surprise could be.
"I love you, and nothing will tear us apart. Now you need to rest, and I need to get a few things for tomorrow."
I kiss her and leave the room.

I'd love to frag her, but I don't want to cause her pain. That will be part of our vacation when she's recovered. I am glad I can order a cake with a custom message and flowers to pick up tomorrow.

"I understand it's very last minute; unfortunately, my original plans changed, and we're celebrating her birthday in the hospital," I explain to the baker who told me I should have planned this at least two weeks ago.
Once the orders are placed, I go to get takeout for dinner. I'll save cooking (Y/N) her favorite dinner for tomorrow.

(Y/N) is happy with the takeout I return with and excited when I tell her the surprises for tomorrow are planned. She's not ready to leave the medbay even though Ratchet tells her she can for a while. (Y/N) is asleep soon after we finish dinner.

The next day

(Y/N)'s P.O.V.
I can't believe how fast Mirage planned a day of spoiling me. Starting with breakfast, I don't have (non-healthy breakfast) often. Ratchet wants me walking around and tells me the pain medication should last six hours as he removes the infusion line from my I.V.
Walking still hurts a little as Mirage and I walk to the lounge room. Jolt follows us to see how I'm doing walking.

"Now, we watch one of your favorite movies," Mirage says as he sits next to me, "the movie should be over before the pain medication wears off."
It's a nice morning until my pain starts to come back. I'm back in the medbay, and Mirage goes to start making my favorite dinner. Meanwhile, Jolt wants to start physical therapy.

Mirage returns two hours later, hoping I'll want to go to the cafeteria. There's no way he could pull off a birthday party in twenty-four hours, but I know the others want to see me.

I walk down the hall into the cafeteria, and sure enough, most of the Autobots and soldiers are there. Even though they're not hiding, they still tell 'surprise.' Some laugh afterward.
"It's hard to pull off a birthday party, I got a lecture about ordering one personalized cake, so I doubt I would have been able to get enough for everyone," Mirage explains.
"It's still a birthday party," Sideswipe adds.
Mirage wheels me to a table and gets our dinner.
"I said I'd make your favorite," Mirage says as he puts the plates on the table.
"It's hard to believe you didn't have a backup plan."
"I didn't, but even if I did, it would be hard to plan a party thinking just in case my original plans fall through."
"So we would have been heading to your surprise destination today?"
Mirage nods, "it is a vacation, but I'm not telling you where we're going until you have recovered."
It's a nice time together, and I can't wait for our trip.