It was probably when she felt Don get up in the middle of the night to check on him when she realized.
Cosmo had come to Don’s place drunker than a crew of sailors, only landing on their doorsteps because he had come by so many times he could do it in his sleep. Kathy had been staying over like she always did now that she and Don were (finally and actually) engaged and had opened the door to him grinning up at her, singing some song from Annette Hanshaw she didn’t recognize. He had conked out a total of seven minutes later.
She and Don slept in their bed upstairs while Cosmo slept in the guest bed than had been revealed to be one of the least comfortable things in the house (besides maybe the heels that Kathy’s mother insisted she wore whenever visiting, Don had said cheekily, and she had to roll her eyes but agree) because they had refused to carry him up the steps to his own little room. She had managed to fall asleep, but it was exceptionally light, so she felt it when Don sat up next to her and left the room. She waited a moment or two to hype herself up before rolling out and joining him, making her way downstairs.
Kathy had known about Don and Cosmo’s history since the very beginning, but she never saw it laid out so desperately as in the way they danced without planning, the ridiculous inside jokes that they exchanged purely through looks, and right then. Don was standing next to the bed and he had a hand curled through Cosmo’s hair protectively, and Kathy could see the past that held up the strings of that action. She walked over to him and leaned into his arm, making her feel like some sort of large boulder, forcing water around her. But Don pulled her in tight and she let her head drop on his shoulder and her hand creep down to Cosmo’s, and she inserted herself into the flowing of time.
When she thinks about it all- how a life she was only moving through unhappily, unsatisfied, was the one she thought she would live forever -she realizes she’s never felt as safe as she has in Don’s arms with Cosmo beside them.
This, she knows, is where it really starts.
In the world of Hollywood, you’re either fifteen minutes early or you’re late. Don is a humble man, however, and thinks you only need to be five minutes early (Though- he muses -it may because he’s so popular that people are willing to bend a little bit, exasperated). Even with his great standards, Kathy was at least seven minutes late.
He and she got to get away for once and were going to a sandwich place that was hidden away from where they would almost definitely get harrassed and had actually good food. It had taken a lot of searching to find something quite so nice. As much as Don liked to idle, he was hungry and also he always liked being with Kathy, so he figured he should at least search for her.
After poking his head in a dance rehearsal and nearly ruining a picture that had been filming right that second, he found Kathy leaning against a piano with her eyes closed as Cosmo played for her. It seemed quiet and intimate, and he almost felt guilty for walking in on it, until Kathy cracked open an eye and spotted him, a full-blown grin lighting up her face.
She shimmed over, Cosmo still playing, and kissed him gently, which made Don feel woozy. “Where’s my kiss, Mrs. Mr. Lockwood?” Cosmo joked from the bench, and Kathy just shook her head.
“If you want one, stand up and get it,” she replied, which he scoffed at.
“Ah, trying to get me to move something other than my hands. Crafty, crafty.”
“We still on for lunch?” Don interrupted, wrapping an arm around Kathy’s waist. Her eyes lit up in a realization moment before she hit herself in the face.
“I got so caught up listening to Cosmo play, I forgot! We’re still going, though. I’m hungry.”
“Oh, well, we should fix that then, shouldn’t we? Though..” he said, mumbling the last bit before looking at her and attempting to communicate to her solely through a facial expression/blinking language. She just looked confused before he remembered she was good, but hadn’t known him quite long enough to understand past ‘I don’t speak blink’ and ‘Get out of here before I rip your teeth out.’
“Cos, you want to join us for sandwiches?” Don asked, and he could almost hear Kathy’s ‘Ohhh’ of realization.
“If the lady doesn’t mind,” he said in somewhat agreement.
Kathy just smiled lazily, and beckoned him over. So, Cosmo leaped up from the piano bench and linked arms with Don.
At the restaurant, Don didn’t quite know how seating would work, but Kathy didn’t hesitate to pull both men into one side of a booth. Cosmo sat on the inside, Don in the middle, and herself on the last section, where they were pushed together happily.
“We should do this more often,” Kathy suggested around the time everyone was finishing up, and they both nodded.
“There’s this place that has great rice and hardly any murders that I know of,” Cosmo suggested jokingly. “Me and Don have been there before, and the terror himself refused to let me mix honey in with the rice.”
“I think honey rice is fantastic,” she said, laughing as Don groaned next to her.
“It’s just too sweet!” Don protested, though the two weren’t hearing any of it.
“Watch out, Don. I may just have to run off with Kath so we can eat all the honey rice we want if you don’t get married soon,” Cosmo threatened, wrapping an arm around Kathy’s shoulders, which made Don feel warm down to his bones.
“Oh, I’ll just have to challenge you to a duel for her hand then!”
“Boys,” Kathy interrupted, stopping the pretend feud before it escalated to actually pretending to duel with the knives they had been given, and Cosmo and Don just grinned at her like perfect angels.
At first, none of them noticed.
Cosmo would already stay over at Don’s house constantly, so no fits there. Kathy was a fun little add-on, but she, Don, and Cosmo became routine quick enough. Cosmo would make the coffee, she and Don would make the food, Don would find and throw any last minute necessities at people, and all three of them would dance around the kitchen impromptu. Kathy got very good at joining along with the patterns the two boys had years to make, and she was proud of herself for that alone.
Cosmo got to learn how she liked her coffee, she figured out how they liked their eggs, and Don always made sure to keep an extra tie and extra dress in his trailer nowadays. Recently everything has become so routine, and they have all grown to love the mundane in such a way that they fade into it.
The realization is unlike most things in their lives recently: quiet and soft and so overwhelming Kathy thinks she may be choking on it.
The way Cosmo smiles at her when she recognizes a tune he’s playing, how Don will hold her hands even if she’s sweaty and panting and red in the face from dancing, when Don will lean into Cosmo and Cosmo will lean back.
It’s so so quiet and she wants to laugh as much as she wants to cry because it’s all just so much and she doesn’t think it’s anything any of them are ready for. Not so soon after The Dancing Cavalier. But it goes on anyways, and Kathy is almost thankful.
When Cosmo tries to slip through the cracks without notice, she realized maybe he didn’t see it too. So she talked her feelings out with Don who just lit up like a Christmas tree because he hated having to choose but Cosmo felt like coming home and Kathy felt like where he was meant to be the entire time.
Courting him was a plan. First Don would try to, and likely be successful, then Kathy would swoop in. Hopefully there would be no need for step 3, confessing, but they allowed themselves to think about telling Cosmo about the way their heart pumped out blood for him and for each other.
Don dressed up around the house and made Cosmo’s favorite more often. He would nuzzle into his neck and lay on his lap, which Cosmo would laugh off. In a more Lockwood-like way, Don switched to playing up charms and flirts, and do everything in the book of seduction that he had written. Cosmo, having read the book front to back a thousand times, was slightly immune. Not totally, but enough that he would let it rest uncomfortably where they wanted to say something.
Kathy was next, giving him quiet private smiles, and requesting more love songs. More silly kisses on the cheeks that lasted too long and noticing too much about Cosmo. Every time they touched, he seemed to thrum with questions he felt he couldn’t ask, and Don began to notice under his caring hand too. Closer, closer.
It’s the night the air is cool and Cosmo’s car breaks down after seeing a picture just casually that they lock into step 3. They manage to get it to a hidden road just in case, even if it’s so late out that nobody but the wild would be walking the streets, and Don pulls Kathy close to give her a little kiss as they lean against the side of the car.
“Where’s my kiss? It’s my car that’s down,” Cosmo joked, knowing it would magically come back to life in several minutes. Don and Kathy gave each other a look, and Kathy didn’t even need to know blink to understand what Don was asking.
So, he nodded to himself and untangled their limbs, Kathy watching on like her life depended on it. She was scared of the conclusion that what they were about to do would bring, because what if they were wrong?
What seemed like a lifetime ago, she asked the same question regarding her choice to stay in Hollywood and pursue a career in the talkies rather than ultimately go to New York, like she had been saying since she was twelve and her brother died in the war. It had gotten her Don, it had gotten her Cosmo, and it had gotten her success. When she thought about the choice she would often become overwhelmed with something she couldn’t place, but she was pretty sure it was the feeling of almost losing your home.
Seeing Don step close into Cosmo and grab his face, she’s sure she can feel the west wing crumbling down onto the Earth, and it hurts. The two men’s lips come together and Kathy almost cries thinking about the remodeling they’ll have to do after every part that Cosmo ever resided in turned into nothing but smithereens, she can see it’ll happen in Cosmo’s wide eyes.
They’re pushed against the car, but Cosmo threw his head back to avoid Don anyways and looked to Kathy in terror. She swallowed her fear like she would a drink when trying to prove Don wrong and walked over, shoes clacking against the gravel. It’s only a few steps but it feels like she walks five hundred miles when she arrives next to both men. She stretched an arm out next to her on the car and leaned in near Cosmo and his breath was hot on her face until she plugged his mouth up with her own, just a peck, before pulling away.
Cosmo blinked hard, his whole face scrunching up in some show, and he paused to breathe in and out. “This isn’t a trick or pity against me, is it?” He asked quietly.
Don smiled at him lazily and shook his head before replying, “Honest.”
“Honest,” Kathy repeated, her mouth dry, like it was filled with cotton. But she still had to answer him the way she had been looking to for weeks. She couldn’t just subtract herself from the equation.
“Oh,” he said, and his voice seemed to have gone up a little bit. “Well, that’s new.”
So close and so quiet, she realizes how long Cosmo’s eyelashes are and that alone makes her giggle quietly until it roars up with emotion she’s held back and she’s gone. She’s got tears in her eyes and she’s snorting, her trained laugh that the studio is trying to get her to stick to disappearing. Don grins at her with a sparkle in his eyes and eventually joins her. Cosmo is the only one left, but he gets pulled into it, never resisting a good laugh.
She finally calms down sitting on the street, and she’s breathing heavily. Two different hands are wrapped around hers and the street is silent until Cosmo’s car purrs back to life. The three wait a few more minutes before climbing back in.
It’s not easy, not at first and not soon after- there’s still so much history to dig through and sort and plenty of things that need to be hashed out and they still need to hide everything from everyone -but nothing ever is and they knows they can figure it out: together. Because they’re determined to all be happy, to love and feel the way they want and need and should.
But when Cosmo sings “Fit as a Fiddle” and Don offers to teach Kathy the steps, they all grin. When Don and Kathy fight over who’s going to not do the dishes, Cosmo watches amusedly before bringing in a guitar he stores in the music room and plays music you’d hear in a western showdown. When Kathy sees the article speculating she and Cosmo cheating on Don and cuts out the article to tape their fridge, and she makes little hearts around all their heads.