Disclaimer: I don't own Lost In Space or its characters, etc. etc.

Author's Note: The reboot series is so satisfying that I never thought I'd feel the need to write fanfiction for it. But alas, I did find myself greatly missing Don & Judy's banter in season two. Honestly, they could've left it at friendly teasing and I would've loved it. Anyway, my brain felt the need to explain why it disappeared between seasons.

Timeline: Between Season 1 & 2; while stranded on the "water planet"

Don West's com beeped just as he was elbow deep in the coolant system, making him start and hit his head on the edge of the metal panel. He cursed as Judy Robinson's voice crackled over the device.

/Don, I need your help with something./

The pain made him wince as he rubbed at the back of his head, but he pressed a button on his wrist com. "What is it, doc?"

/Um… some sort of malfunction… in my room./

Don closed his eyes, took a deep, steadying breath, glared at the patched system that was barely holding it together, and replied. "I'll be there in a couple minutes."

/Thanks./

"Robinsons… gonna work me to death," he told Debbie. The chicken cocked her head, obviously not falling for his griping. "What? Don't look at me like that."

He picked up the pet hen he'd never intended to be anything more than a future meal and made his way through the jupiter that had become his home over the past few months. Debbie didn't even squirm when he carried her now. He thought she rather liked it. But when he set her down in his room and told her to be good while he helped Judy, she gave him a scathing chicken glare.

"It won't be long," he said. "I promise."

She clucked and showed him her feathered backside as she went for her food dish.

"Don't be jealous. There's plenty of Don West to go around."

/Don, where are you?/ Judy's voice rang out more clearly over his com this time. There was a bit of an edge to it that had him in a partial jog as he hurried to her room.

Her door was closed. He frowned, raised his hand to press the chime but it slid open before he could press the button. Judy's attractive face appeared, her big dark eyes skimming over him and then glancing up and down the hall.

"What took you so long?" she asked.

"I-" Before he could finish pointing out that it had only been two minutes, the young doctor grabbed the front of his t-shirt and yanked him into the room, closing the door behind him.

"Judy…" He drawled her name in warning, wrapping his hand around her wrist, but she kept her fingers twisted up in his shirt and yanked on it, hard, pulling him down and crashing her lips against his.

Her kisses were electric. Just like her. Vibrant, scintillating. Irresistible. They had a tantalizing exuberance that he only remembered last experiencing when he was in his early twenties, over a decade ago. Son of a-

He broke off the kiss, tried to ignore the bewildered hurt in her eyes as he placed his hands on her shoulders to push her away.

"What's wrong?" Her chin lifted in that stubborn bravado way of hers. "Did I interrupt something important? I thought you were just tinkering with-"

"That's... uh… That's not it."

She raised her eyebrows, those perfect, kissable lips of her persing.

"We shouldn't…" He scrubbed a hand over his face. He wasn't used to refusing female attention. And more than that, he liked Judy. A lot. "I mean you're…"

She silenced him with a glare. But he knew better anyway than to tell her she was only 19, too young, not an adult. Because she was one of the most responsible, wise, compassionate, badass people he'd ever met. Hell, she was more of an adult than him. He also should know better than to point out that her parents wouldn't approve, would probably kill him. Because Judy herself would kill him for making such an intimation, that she wasn't capable of making decisions for herself, that she didn't consider every situation thoroughly before choosing a course of action. He knew better, and yet…

"Coward." She caught his gaze. And damn, she was beautiful when she was fierce. And Judy Robinson was always fierce. "You're afraid of getting close to anyone. But whether you like it or not, this family cares about you. And you care about us. And you care about me." She stepped in closer, her breasts -which he tried desperately not to think about- brushed against his chest. "And you like kissing me."

She pulled him down into another kiss. He opened his mouth to her, unable to resist the intrepid probing of her lips, her tongue. And she was delicious. Not just sweet, but complex. Judy Robinson was so complex, so interesting. So… so… Oh, god, so good.

Her hands had flattened against his stomach, were roaming up to his shoulders. She had skilled doctor's hands, and so many parts of him wanted to discover just how skilled they were at tasks besides medicine. They slid back down his chest, fingernails scraping through the soft fabric of his t-shirt, raising goosebumps across his skin, making him groan into her mouth that continued to devour him. His own hands gripped her hips reflexively. She had such a feminine, athletic body, strong and beautiful, and pleasing to the touch. So strong.

She'd backed him against the cot, pushed him to sit on it, giving his tingling mouth a break. Oh, hell, he was aroused. He needed to put a stop to this before things really- Damn!

Judy was up in his lap, straddling his legs, moving in for more devastating kissing, kissing that would doubtless lead to more than kissing, which he couldn't allow. She was 19 and the Robinsons' daughter. He liked them. He liked her. He turned his head, thwarted her hungry mouth, but only momentarily, for she kissed and nipped along his jawline instead.

She was certainly a woman who went after what she wanted. Only, he couldn't give it to her.

He grabbed her shoulders and held her away from him… Well, partly away from him. There were still portions of their bodies in dangerously close proximity. She made a frustrated noise, and gave him her biggest pleading puppy dog eyes. But they weren't going to work this time. Because the right thing to do was to stop this, stop her randomly calling him for secret rendezvous, pulling him into vacant corners for stolen kisses, looking at him like she might just be-

"You're a smart young woman, Judy," he said. "I mean, I have my moments of genius..."

He winked at her, making her smile. She stroked the nape of his neck, affection warming her features. He ignored how much he liked her gentler attention, because he had a point to get across.

"But you're way smarter than me, doc. You must know that the only reason you want me is because I'm the only option here."

Her soft, dangerously affectionate look hardened and he knew he was one small prod away from waking her stubborn temper. But it had to be done.

"It's probably been awhile for you. Hell, it's been awhile for me, too. But you can do better than me, princess. And when you get out of here, get to where you're going in life, there will be some fancy pants egghead waiting for you."

"Just… Just shut up, Don. You don't know what you're talking about!" There was a pink hue coloring the gorgeous brown skin of her face. Her lips screwed up, a line forming between her brows. Her thinking face. She took a deep breath, met his gaze directly. Her eyes were always almost unbearably intense, showing all of her passion and intelligence. She wet her lips, surprising him with the nervous gesture.

"I'm not desperate for physical companionship. I genuinely like you, Don West. And if you can't believe that…" Her eyes shimmered, but she was still wearing her tough face. "I'm sad for you."

She removed herself from his lap, and it was a loss that made the bottom drop out of his stomach. She walked towards the door, not looking at him, an obvious dismissal.

It was for the best. It was.

"Oh, and Don…" He paused, so close that the scent of her, somehow fresh despite months of recycled air, filled his head. Her warm, dark eyes met his. "You would've been my first…"

"Fi-irst?" He nearly choked on the question, felt his mouth go dry. But felt his uncertainty fade ever so slightly. He had done the right thing, putting a stop to this… whatever it was between the young doctor and himself.

Wait. Was her mouth twitching?

"I didn't mean like that," she said. Then all amusement fled her. "I've just never felt…"

She closed her eyes, huffed, her cheeks turning pink again. He couldn't blame her, he was feeling heat creep up his own neck and face. Their interactions always had been primarily light-hearted teasing and fiery exchanges. Deep discussions of feelings was not on his favorite things list, either.

"I think I could fall in love with you," she said, her eyes finally daring to find his. She was so beautiful. Why did she have to be so beautiful, inside and out? So brave and strong and noble. So stubborn and mouthy. So Robinson.

"Oh, princess. I already love you." The words were hard to get out, hard to say, and they emerged in a whisper he could barely hear himself. "But I love all of you stupid Robinsons. And I won't do anything to hurt any of you."

He jabbed the door control with his thumb. He needed to get out of there, away from her, the summer-breeze scent of her hair and skin, the consuming depth of her warm dark eyes, the pull of her kissable lips and smart mouth…

"You wouldn't hurt me," she said. He turned to give her a bittersweet smile, finding her standing tall with her arms crossed in front of her chest, that adorable set to her jaw. A warrior through-and-through. "I'm tougher than you think. Even if things didn't work out..."

"I know you're tough, Judy. You'll get over me in no time. But I can't lose the Robinsons."

Don West walked out the door.

He'd done the right thing.

END

A/N: I actually hate criticisms of fictional (or real) relationships based on age differences. If they are two adults, then age is not what matters, not as much as compatibility, respect, etc. But at the same time, I would've been okay with Don & Judy just being friends, and wish TPTB had kept that teasing banter of theirs! My brain felt like putting a romantic-based reason for their shift in interaction in there.