Kat got her men in the end, Marinette her man. Nathanael and Adrien learned to accept their feelings for eachother and Kat and their relationship grew much healthier. Felix got his Ladybug, and learned to love his Marinette too.
Of course things weren't all sunshine and roses, no relationships are.
Felix remained aloof and insensitive to Marinette. They often snarled at eachother over his unfortunate habit of thinking too highly of his love, which caused him to do unnecessarily risky things to protect her. This had nothing to due with any idea that Ladybug was INCAPABLE, but more of a fear of failing her…letting her get hurt.
"It's fine…" Felix declared, after sustaining yet another injury when throwing himself into danger recklessly.
"Actually, no it's not." Marinette argued, trying to put ice on the large bruise that was forming on the part of his left cheek that was not covered by his mask and thus able to sustain injury. "You should refrain from such reckless behavior."
"I'm only reckless because I need to protect you, My Lady." He tried to send her his little smirk, the one that Marinette could never resist. He winced as the action bothered his injury.
"Don't you "My Lady" me! Do you have any idea how…how AWFUL it makes me feel?" She huffed. "I don't want to lose you. My life isn't more important than yours!"
Felix chose to wait for her to finish her rant before replying because he was smart enough not to make her angrier with an interruption.
"What if I started acting like that? How would you feel? How DID you feel?" Marinette did it once, when they were up against one of the most dangerous Akuma to date; Kat.
Felix bit his lip, remembering how it felt when Marinette threw Kat out of the way. The moment of sadness that crossed her face before he had to watch as the love of his life was unceremoniously chucked off of the Eiffel tower and he just froze, not knowing HOW to save her, before jumping after her to try and save her.
"Don't you get that I NEED you to be safe in order to function properly." Ever since that image was permanently branded into his brain he was even more reckless, never wanting to have that experience again.
"Let me phrase it this way; if something happened to you, would you want to make me feel like that for the rest of my life?"
"Of course not. But your powers allow you to just fix everything in the end. I can't do that so I have to prevent something bad from happening to you."
"What if it didn't work? And you were gone?" She replied, her insecurity and fear showing through her anger.
"Then Kat will use that time machine that she denies exists." Kat got bored of the physics and parodoxicality equations in about ten minutes. It's somewhere hidden in the back of her lab.
"Right. Since there is that time machine that I forgot about, thanks for reminding me, it would serve to bring me back as well, right? So you have absolutely no reason to do such things."
"But I would know that I failed you and that you were gone and that everything is awful."
"Felix…you don't even have the Lucky Charm. I would have failed you, even with the lucky charm…" Even as Ladybug, "Wait. That…That doesn't matter. What DOES matter is that you are by no means disposable, and treating yourself as such hurts me an awful lot. So I'd demand from you to…" She sighed weakly, "Just, just stop this. Okay? Will you at least try to?"
Felix couldn't say no to that earnest look on her face. Of course, it did only take a few days before he was right back to his old tricks. And the argument restarted once again.
Kat would've been annoyed by their fights and the way Marinette and Felix were at eachothers throats as much as they were in their bliss. It would've been hypocritical for her to do so, however. She and her boyfriends weren't exactly a walk in the park.
It should've been obvious from the start that that was going to happen, though. With Adrien and Kat you get two loud, passionate, and headstrong lovers. Nathanael, as sweet as he was, was often one to make the arguments worse by agreeing with one side or the other even accidentally one of them could take his words to mean they agree with the other's side.
Usually their fights are over inconsequential things. Who would win in a fight between Franklin Richards and Ichigo Kurosaki, or when Anime passes the line into becoming porn, who the three of them should go to Comic - Con as, or that they were FLIRTING with someone else to make them jealous.
Nathanael would usually be coerced into creating art for his two loves. He did it because he loved them (and he seriously could NOT say no to their puppy dog pouts, that much cuteness should be illegal).
That isn't to say all their arguments are juvenile.
Sometimes they all had to be reminded about what is important. Nathanael sometimes gets upset that he is basically Lois Lane and he had to sit back and watch Wonder Woman and Superman save the day. (Adrien was NOT Batman, no matter how much he pretended he was.) Kat has to be reminded that she was just as important as the other superheroes and the fact that her father had extremely high expectations of her, no matter how much she exceeded everyone's expectations she could never meet up to his, wasn't her fault. She also sometimes got too busy wrapped up in her own mind to remember things she needed to do. Adrien needed to be reassured that he was important and necessary and without him they wouldn't be able to succeed.
They weren't perfect, but they were happy. Even when They had to make eachother feel better because they learned the world in their civillian forms were so much more difficult.
Kat said it best. "Look, when I am the Cheshire Chat, my enemy is a person. It is a physical, tangible being. I can punch the manifestation of my problem. I can't do that all the time. The world is full of concepts and problems I can't deal with it easily. It sucks. Life isn't an akuma who just needs to be purified."
They all had each-other, and even Felix had to admit that is enough for the group of them to deal with.