Disclaimer: Not mine.

Usual caveats: I'm German. Please bother to correct me if I messed up grammar or anything else.

NB: the entire continuity goes off-canon shortly after 'Enter the Nightbird', so no Protectobots and no Aerialbots. Red Alert is actually a stretch, but he's too much of an institution to be left out.

Notes: this begins approximately 5 seconds after "two worlds apart, two together" leaves off. You might want to read that story before you delve into this little monster. I actually considered just adding this as chapters three to n to "worlds apart", however, it's rather different style-wise, so it felt wrong.

I've come to call this a little monster because it started with a reader's comment on the phrase 'betrothed', kinda got out of hand, (much like Audrey II) and ate a lot more time and hard drive space than I expected

That said, I'd like to thank everybody who left a comment and/or favorited 'worlds apart'.

Title once again by Sisters Of Mercy.

Oh, yes, for everyone who ignored the summary: This be slash, so don't read if the idea squicks you out.

all your hidden faces

1

"So," Optimus said and opened the door for them. "These are my… our quarters."

Ah. Starscream was supposed to move in with Prime? Just like that? It had been ages since he had shared living space with anyone, and he'd hated it back then; how they always seemed to need or want something and how they always smothered him with their mere presence. Even at the thought he felt his wings hitch.

"After you," Optimus said.

Starscream slipped past him and tried to keep the unease under a lid. It couldn't hurt to inspect the place.

He found himself in a living area, desk and computer access in a niche, couch, low table, small entertainment center, energon dispenser. Nice. Captain's quarters of any large cruiser, and much better than officer's quarters on the Nemesis. Better than Megatron's quarters, too.

"In there are the washracks," Prime pointed to a door to the left, "and in there is the bedroom." Door to the right.

Starscream nodded and went to peek in both rooms. The berth was large, it could fit both of them easily. A few personal knickknacks on a shelf to know someone actually lived in this place.

"Hmm. What is in there?" There was another door to the left.

"Just a guestroom."

Oh? Starscream moved over to have a look.

It wasn't too big, just a berth, a few empty shelves and a desk with computer access. More a room for a sparkling than a guest room, but he wouldn't tell Optimus that just yet. Better than having his own quarters and providing cause for rumor whether he'd spent or not spent the night. "It will do."

"What?"

The confusion was palpable, and Starscream turned to look at Optimus levelly, willing him to understand.

It took a while, and the part that was Optimus clawed for hints. "Oh." Someone was actually offended.

"I sometimes do require some privacy," Starscream snapped and used his newly appointed room to have just that. How dare he.

"Starscream?" The voice was slightly muffled by the door. "Please. I'm sorry."

And he was, the bond said so. Totally crestfallen, and maybe Starscream had overreacted. It wasn't even a sparkbond, sometimes it didn't transmit at all, and Prime couldn't read minds. That bond was effectively refusing to let Starscream pout, made him want to fix things.

Starscream opened the door and stood in the doorway. "You see what I mean?"

"Yes." There was a gentle smile, and it wasn't covered by the mask. "Thank you."

"Whatever."

"If you want some time to settle in…?"

"I'm not a human, Optimus. I don't have any luggage I could unpack."

Now he was confused.

Starscream owned exactly three things. A picture of Skyfire and himself, which for some reason he had never been able to destroy, an oddly shaped, red crystal that was once decorating his office desk (a good luck charm Skywarp had found for him before he left Vos for the Academy), and a polishing cloth. Everything else once in his possession was either on Cybertron, aboard an abandoned vessel drifting around somewhere in space, or on the Nemesis.

There was nothing left he'd leave lying around anywhere.

"I'm sorry," Optimus said eventually. "I wasn't thinking. If you need anything, tell me, and I'll try to get it for you."

Nodding his thanks, Starscream squeezed past Optimus, and was held up with a feather light touch on his arm. He stopped to meet Optimus's intent gaze, and something inside him melted.

This was why he had come here, after all.

Expelling some air from his vents, he moved in closer and let himself be kissed, slowly and luxuriously, giving them time to explore.

Before the heat could build up, Optimus withdrew. "There are some things we need to talk about."

Unfortunately, yes. Starscream let out another sigh and tilted his head, asking Optimus to begin.

"Sit with me."

Stalling? Starscream followed Optimus to the couch, but went to straddle his lap. He didn't particularly like back rests. It took Optimus a few moments to get over his surprise at the arrangement, but it was definitely worth it. Keeping Prime off kilter was something he'd effectively been asked to do by the mech himself.

Eventually, Optimus' hands settled on Starscream's hips, lightly, like a pair of birds that expected to be startled any moment.

"What did you want to talk to me about?", Starscream reminded Optimus of what they were supposedly doing.

"About this bond we share… it could be broken, if you'd like to. I'm sorry. I should have known better than invading your privacy like that."

That was the apology he'd been waiting for. "I don't particularly mind it." Not quite a lie. It was comforting, in one way, and it was extremely gratifying in another. It didn't leave him guessing like Skyfire had. "What is it, anyway?"

"It's called an encoding. It's more a specialized, secret comm. channel than a true bond. That's why you can shut off the receiving but not the transmitting or vice versa."

And it explained why a separation wasn't quite as crippling as with a sparkbond. Starscream nodded his understanding. "You have some material on this?"

"Borrowed without asking from Ratchet."

"Tssk," but he couldn't hide his grin. Prime rule breaking. Who would have thought.

Optimus gave an embarrassed little smile of his own. "Second," he started. "Everyone will expect us to be sparkbonded once we emerge from out here."

Starscream nodded again. "I'll try to act reasonably love struck, then."

"It's not that. I hate lying to them."

"We are bonded. Only it's not a sparkbond."

"But it's what 'betrothed' implies."

"I won't sparkbond with you just because you have a bad conscience."

"I didn't…," he was crestfallen again, and there was this look in his eyes, as if he were a kicked sparkling. "This is not a roundabout way of making you agree. I…," the hands on Starscream's hips tightened and relaxed their grip once. "Just some sympathy, perhaps?"

"Hmm." It sounded more like he wanted absolution than sympathy. Starscream leaned in for a short kiss. "That tactician of yours does know what's going on, right?"

"Not everything. But he suspects."

"So talk to him," though he didn't like the thought of Optimus confiding in anyone else. "He'll tell you it won't make a difference whether they know or don't know. We are bonded, and it's not their business how or when we went about it."

"Thanks."

It sounded so honest, it made Starscream lean back a little. He definitely didn't deserve that. "Whatever. Was there anything else?"

"I'll go out and face the cavalry in the morning. I think it's wise if you stayed here until the worst is over. And… you can't always stay here or tag along with me."

"I know… I need to have a talk with Skyfire." And he dreaded it more than anything, but the shuttle was a potential ally.

"Good," said Optimus, though he sounded hesitant. He'd probably felt the trepidation. "I'll send him over as soon as I see him."

"You mean I can invite him here?"

"Mi casa es su casa," Optimus said. "These are our quarters. You are not a guest here."

Good. Though there was some unrest in the region of his fuel tank, as if he only now realized what he'd gotten himself into. This was a permanent arrangement. Speaking of which. "I'll need to refuel soon."

Optimus blinked at him for the non sequitur. "You don't have to ask, but I do have something that I've wanted to share."

Getting the hint, Starscream climbed off, and waited for Optimus as he rummaged around a closet under the screen in the wall and found some cubes and a flask of glowing high grade. A half full cube was eventually presented to him, and Starscream sipped at it carefully. He and high grade didn't mix very well. Some construction error, probably.

They sat down, Starscream on an armrest and Optimus reclining, both appreciating the energon. Occasionally, their optics would meet, they'd trade a small smile, and then both would look away quickly, starting the game anew.

It was a long time since Starscream had flirted that way, and surely never with someone who was already his. (Though there had only ever been Skyfire.)

And yet, it was a nice way to let the anticipation built up.

Eventually, the high grade was gone, Optimus collected the cube and returned everything to its rightful place, and then he stood in front of Starscream and looked at him with his inscrutable face.

There was no warning through the bond as Optimus bent down and just picked Starscream up, groaning a little from the effort.

"Let me down." The high grade made his world spin, and Optimus's rather precarious grip wasn't doing his fuel tanks much good.

"No."

And so he was carried to the bedroom door, where things got a little awkward until Prime managed to hit the button with an elbow. A few rather awkward steps more, and Starscream was deposited on the berth, and it hurt his aft because Prime really wasn't as slow in doing it as he should have been.

"Were you trying to be romantic?" Starscream glowered at him.

"I failed, I know. However." He came closer and closer and pushed Starscream back. "I do like the outcome."

Oh, nonono, he'd sure get crushed, and Optimus hesitated. "What happened?"

Starscream lifted his head. "It was an accident, really. Not something you would accomplish." Prime wasn't big enough to be in that particular kind of accident and definitely not heavy enough to put dents into the wings. No reason to refuse him a bit of pleasure.

"Good. Are you sure?"

Strascream nodded past the apprehension, and lay back down. Someone had painted the ceiling a light blue.

"You're not," Optimus stated very calmly, and there was a small pang of regret somewhere. "Besides, your wings are in the way. Sit against the wall for me, please?"

Starscream scooted back, feeling rather surreal. Everyone else would have insisted he just take it. Might have made a show of listening and agreeing and then promising to make it worth it and to stop when he asked for it… but wouldn't have entirely given up on the concept.

"I'm not everyone else," Optimus said. "And I do want to make it worth your while. Which I can't do if you detach yourself like that." He made a little shooing motion for Starscream to go on make himself comfortable.

And only then did he move in to straddle Starscream's hips and nip his way along his jawline until Starscream complied and tilted his head back and then Starscream forgot that he had wanted to retaliate, hands hanging on to Optimus's head for dear life, because it felt so, so good, as that warm mouth found every gap in the soft plating and moved it to get to the cables running directly underneath, sending little shivers into his core until he thought he would explode, and it was making his dataports itch and he whimpered, actually whimpered when Optimus moved on, further down, replacing his mouth with his hands, firm thumbs down the rim of his cockpit, up his flanks, tickling the dataports, and then on his wings, lingering on the flaps, rubbing just so.

"Please…"

"Please what?" Optimus nearly growled into his audio.

To stop teasing make it end and more please.

"Just let go…," crooned Optimus.

Hands back to his shoulder vents and then the mouth again, glossa tracing the inside and teeth nibbling the rim and oh why had no one ever thought to do that before. Mouth moving to the other vent, "let go…", fingers tracing the dataports and massaging and stroking and pinching and sweet merciful release, static turning his sight into blue arcs and making him groan and cling to Optimus as he shuddered.

Maybe Optimus groaned, too.

Reality returned slowly, he'd never thought anyone could do that to him without interfacing.

"Hmm," Optimus said. "And you took me right along, too. Such a bond does have its perks." Slowly, he disengaged Starscream's hands and arranged the both of them the usual way, Starscream on top because of the wings, and Optimus tracing random patterns on his helm.

There was a deep, warm feeling emanating from Optimus, and Starscream drifted into recharge to it, feeling safer than he'd ever felt before.