A bit rough but after reading some amazing fix-it Lotura this was rolling around in my head and I just had to get it down.

"It means so much to me to share this with you."

Lotor sat in front of Allura, pulling up the interface with the slightest flick of his fingers, heart thumping faster than ever before. His words still echoed in his head. He meant every one.
"Beginning systems check."
This was the trip of a lifetime and there was no one he'd rather share it with.
His hand drifted across the screen, selecting menus, checking the ships' controls, ensuring everything was working as it should.
"Front and rear stabilisers?" He prompted.
"Front and rear stabilisers are go." Allura replied.

"Quintessence collection array."
"Quintessence collection array is go."

His heart beat faster.

"Infracells."
"Infracells up."

His mouth went dry.
He shouldn't be doing this.

"Dynotherms."
"Dynothems connected."

He shouldn't do this until after he had told her.

"Switching on mega-thrusters."
"Breathing. Control your breathing. Deep breaths.
It's too late to think about that now."
"Mega-thrusters are go." The princess replied.
The ship began to whir, engines gliding smoothly into action, lifting Sincline slowly into the air.

Lotor vaguely registered the Paladins' loud fretting over the loudspeakers and eventually the black paladin's conclusion that the quintessence field would do them no harm- only reveal what was already there.
"Zarkon was evil- the quintessence field just revealed that." The man said.

"You are nothing like your father."Lotor reminded himself, gripping the armrests in a futile attempt to quash his unease. "There is no evil to reveal. Your intentions are noble. You are not your father."
The bay door lock swivelled and the doors pulled apart.

"You are not your father."

...But are you really noble if you keep something as important as this from her?

He pulled back the lever and Sincline shot out of the hole into space. Daibazaal rushed closer and closer and he stared with morbid fascination at its surface for no matter how many times he saw it he would never quite get over the flickering golds and reds of the magma that lined the more superficial scars in the land and the deep, jagged chasms that wove through the rest of it. It carried the odd appearance of something that had shattered quite magnificently and then was haphazardly glued back together and abandoned half-finished.
An endless plume of smoke rose from the centre.

The speakers crackled again, shocking Lotor from his thoughts as the Blue Paladin spoke.
"Allura!"
"Yes, Lance?" Her voice was ethereal, graceful yet always powerful. It was one of the many things he admired about her.
"Get back safe." The paladin continued.
"I will."

They lapsed back into silence and with it came his insecurities again.
You have to tell her.
They drew closer to the planet, passing through its outer ring of asteroids, past floating chunks of debris and rocks larger than a galran command ship, right into the centre where the planet had first been forced apart.
There lay the gateway.

"T-minus ten ticks to gate-entry."

Lotor's pulse was a roar in his ears now.
You've waited too long already.

"Nine."

You can't wait a tick longer.

"Eight."

The centre of the gate opened like a flower. The runes began to glow and an energy shield formed around it.

"Seven."

You'd be lucky if she didn't eject you into space for keeping it from her.

"Six."

Sincline began to glow.

"Five."

The light from the gateway grew brighter and brighter as it opened and Lotor's anxiety grew with it until-

"Four-"

"STOP!" He shouted, pushing the lever forward harshly, propelling Sincline backwards.
For a moment he just waited, breathing shakily and quickly as he heard the paladins' and Allura's cries of alarm.
He watched the gateway slowly close. The rising panic in his chest lessened slightly.
The emperor's relief was short-lived, however, as Allura's concerned words soon permeated his thoughts.
"Lotor? Lotor, what's wrong?"

Slowly, he took in a long, deep breath.
"I can't do this."

"What do you mean?" She was fearful, anxious. He heard it in her tone, saw it in her eyes reflected in the windscreen.
Who knew what kind of terrible conclusions her mind was leaping to, let alone the paladins'?
Zarkon'sson,murderer,torturer,cruelandevil,galragalrazarkon'sson-
He twisted around in his seat to face her, looking imploringly into her eyes, silently begging her to hear him out.
"Allura. I have discovered, in my short time with you, that you make me feel safe. At home. Trusted and cared for."
She didn't speak, unsure of where he was going with it.
"And despite our rocky start-" A severe understatement- "I think I may have grown to-"

"To?" She prompted, breathlessly.
"To truly care for you- to-"
He swallowed.
"I think I may love you."

For a moment she was speechless, a light flush stealing across her cheeks. She shook her head.
"But what does that have to do with the Quintessence Field? Why couldn't you tell me this later?"
"When we were there, alone?" Her eyes seemed to say.

He swallowed.
Here was the bite.
"Because I have been keeping things from you."
He ignored Lance's triumphant crow of "I KNEW IT!" from over the speakers, ignored the other Paladins' concerned mumblings.
"Before we go into the field and make history, I want my conscience to be clean. I want to enjoy every moment knowing that there's nothing to hide, no surprises or monsters in the Vlarpsack. I want you to feel as safe with me as I do with you."

Allura watched him cautiously, the love and admiration that had bloomed in her irises only hours before having wilted slightly, drawing back until she knew more.
It killed him to see it, but it was necessary.
"I don't understand-" She began.
"What exactly have you been keeping from me?"
Itoldyouwecouldn'ttrusthim!Lance,lethimspeak-Let'snotjumptoconclusionsjustyet-I'mwithyouonthis,he'sshadyasheck-
She had to know.

Lotor met her gaze and opened his mouth to speak.