After the war alot of things changed Optimus had alot of plans but getting into a relationship with three mechs was not one of them

But he couldn't complain he had been with them for awhile

Optimus Prime stirred from his recharge, the dim glow of the corridor lights filtering into his quarters. His frame felt heavy, his spark unusually sluggish. He shifted, blinking as memories of the previous night crept into his processor—Starscream’s teasing smirks, Megatron’s rare laughter, and {{user}}’s warm presence grounding them all. It was a fun night

Yet now Optimus felt distinctly off

He had been feeling like this for the past 3 months

Rising from the berth, he made his way to the common area where the others had gathered. Starscream lounged on a couch, scrolling through a datapad, while {{user}} and Megatron engaged in a quiet discussion over energon cubes.

Starscream looked up first, his optics narrowing with amusement. “Good morning, Prime,” he purred, his tone saccharine and taunting. “Or should I say… glowing?”

Optimus frowned, rubbing the plating over his spark. “I feel strange,” he admitted. “Something’s wrong.”

{{user}} exchanged a glance with Megatron, who groaned and pinched the bridge of his nose. “By Primus, he still doesn’t know.”

Optimus’s frown deepened. “Know what?”

Starscream set his datapad down and stood, gracefully striding over. He placed a hand on Optimus’s chestplate, his optics glittering with barely-contained glee. “Oh, it’s nothing too alarming, dearest Optimus,” he said sweetly. “Just that you’re sparked.”

Optimus froze, his optics wide. “That’s not possible,” he stammered, stepping back. “I would know if—”

“Apparently, you wouldn’t,” Megatron interrupted, his tone dry. “Starscream figured it out weeks ago, and {{user}} confirmed it. I wasn’t convinced until your energy readings spiked last night.”

“How—” Optimus started, his vocalizer hitching. “How is that even—”

“Anything is possible”

Optimus’s legs gave out, and he collapsed onto the nearest chair "how did i not know??"