One of the first things the people from the ark established on Earth were laws, much to the 100's disapproval. Murder, theft, arson, all the usual things were punishable by lashings, by pain, by death. It took a while for a council to be established and for the laws to be changed, to be made fair. It wasn't like the ark, where keeping criminals alive robbed the well-behaved of food, water, supplies, precious oxygen, Earth was different. It was a free society and there was enough to go around.
The other types of laws came after that: adoption, marriage, number of children allowed, things like that.
Around the time the council decided on exactly what laws to put down - anyone who was old enough to consent could get married, children were no longer limited, adoption was a screened, careful process but you didn't have to be married to adopt the many war orphans there now were - Bellamy found himself waking up beside Clarke and squinting at her in the dim light of their tent.
"Marry me."
She stirred and opened her eyes, blinking at him, sleepy and confused. "Huh?"
He rolled his eyes and grunted something obscene, so she sat up and blinked at him a few more times. "I'm not asking you for some big white poofy wedding from hell," he grunted at her.
"Well, that's... good?" she said.
"I'm just asking you to legally marry me, wear a ring maybe." He shrugged. "Be mine officially."
She rubbed sleep from her eyes. "Is this is a proposal?"
"That's kinda where the marry me part came in, yeah," he said, eyeing her. "I'm asking you to marry me, princess."
She sat up further. "Yeah?"
"Yeah," he said. "We'll go off, we'll find that guy that does ceremonies, we'll find that nice cliffside you always pause and look out at the view from, we'll stand there, we'll say something soppy and..." He shrugged. "We'll be married."
"You're so romantic," she said in amusement, but there was a note of sincerity beneath her tone. "What soppy things will you say?"
Another shrug and he scrubbed at his hair with his hand. "I dunno," he said. "Probably some shit about how annoying you were to me once and how you worked your way inside my heart and now I can't get you out no matter how hard I try and how I just... wanna be with you for the rest of my life. Maybe raise a family. What about you?"
She met his eyes. "I'd say you were the most infuriating man I've ever met but that I can't imagine my life without you in it anymore, my best friend and my most trusted companion, that I want all those things with you, too, and that I want to be with you forever."
"So is that a yes?" he grunted.
She leant across and pressed her lips to his. "I think we just got married, Bellamy," she said. "We just need to make it official."
His eyes lit up, an ever so slight shy edge to them and he reached out for her. "I guess I better kiss my bride again then."
"I think you better," she agreed and let him claim her for a kiss.