AN: This is a headcanon I've had for a loooooong time and was recently reminded of by a confluence of tumblr tags and asks. So this fic happened. I've no doubt that some people will hate the very concept of this fic but if you are one of those people, please keep it to yourself. For everyone else - enjoy!

"Heterosexuality is not normal, it's just common."

~Dorothy Parker

They've been together almost two years before she tells him.

She's not ashamed. Not even close. This is who she is and she accepted herself for it long ago. Being attracted to - and falling in love with - both men and women is simply part of what makes her Kate.

But as much as being bisexual is part of her, being a child is part of him. And so she doesn't tell him. Not because she's afraid he'll leave her or look at her differently. he won't. But her sexuality isn't for his titillation and, as much as she loves him, she can't help but think that he'll -

Well, that he'll be him about it.

"How many bottles of baby oil sacrificed their lives for that, do you think?"

Castle lifts their linked hands, pointing with one finger at a float of scantily clad men, their skin shining in the blazing mid-June sun. Club music pounds from the speakers and the men dance and twirl, throwing rainbow colored beads and condoms and maybe even a speedo or two into the cheering crowd. Kate can't help but smile, the joy of the day infectious.

"I'm guessing a minimum of seven," she laughs, reaching up with her free hand to catch a string of beads. Castle lets her loop them around his neck, adding to the growing pile. "But at least they didn't die in vain. That is one good looking float."

"Gonna trade me in for a younger-" he cranes his head to look at the float, already halfway up the block - "far more buff model?"

"Pretty sure that you're their type, stud, not me. Besides," she says, lifting up on her toes and looking the opposite direction down the street, a grin playing at the corners of her lips, "that is more my speed."

The rumble of two dozen revving engines fills the humid air, bouncing off the brick buildings. It buzzes in her veins and Kate leans forward, pressing her exposed midriff against the hot metal of the gate at the edge of the sidewalk, a corral for the spectators. The first bike rolls into view, a sign proclaiming the name of the club affixed to the front.

Dykes on Bikes.

"You do love a good motorcycle, don't you?"

"Even a bad one," Kate agrees. Not that such a thing exists. "The women riding them aren't too bad either," she says, the words spilling past her lips without first passing through her brain.

Castle opens his mouth to respond but the deafening roar of the motorcycles drowns him out. One of the bikes passes close to them, the driver dressed in leather and a young woman with a rainbow painted on each cheek straddling the tiny back seat. She leans over, arm extended and a rainbow patterned flag clutched between two thin fingers.

Kate takes the wooden stick and waves the little flag before spearing it into the bun sitting on top of her head. The girl whoops, arms lifted high over head and hips wiggling. Another float - this one full of parents and children - passes by and Kate feels a tug on her fingers.

Time for this, then.

"So," Castle drawls, leaning close to her, far closer than he has all day in deference to the heat and the press of the crowd. "You -"

"I what?"

"You - Well, it seems - From what you said -"

Laughter bubbles up in her chest and Castle gives her an adorable pout, his chin wrinkling in that way she loves. She can see herself in the mirrored lenses of his sunglasses, her face flushed and hair full of glitter.

"Dammit, Beckett," he grumbles and she laughs again, the decision to take pity on him coming easily.

"As you've obviously deduced," she says, reaching up to flick the end of the flag off her forehead, "yes. I am -"

"Attracted to women," he interjects and she nods.

"Bisexual," Kate fills in, using the identifier she prefers.

Castle stares at her in silence for a beat or two and she holds her breath, heart jumping against her ribs. This could go -

"You know," he says, head cocking to one side, sweaty hair poking out in spikes, "I think I might have already known that."

Her bark of laughter draws stares from a few of the people around them. "How could you have even?"

Castle shrugs, his biceps straining against the tight blue cotton of his t-shirt. "Looking back on things - knowing it for certain - it seems sort of obvious now. Like, the beauty queen murder? I so should have seen it then." His head rocks back, a frown pulling down the corners of his lips. "How did I not see it then?"

She pats him on the chest, her engagement ring glinting in the sunlight. A foil packet bounces off his shoulder, landing abandoned on the edge of the street.

"I'm pretty lowkey about it," she consoles with a one shouldered shrug. "I'm not ashamed but at work I keep it quiet because, well -"

"People are judgmental, juvenile assholes?"

"Basically," Kate laughs.

A float with the cast of some television show passes by, Madonna blaring from the speakers. A mob of people dance around it, all of them doing their own version of Voguing.

"Is that why you've never told me? Because you thought I'd be a jerk about it?"

The tinge of sadness in his voice slices through the thin skin at her ribs, stabbing directly into her heart. It is why but she should have known better. Should have had more faith in him. Dammit.

Kate nods. "I'm sorry. I've had a few bad experiences with men who think that it means - Well, that it means a lot of things it doesn't. But I should have trusted you more."

"It's okay. I get it." He kisses her temple and she leans into it, eyes fluttering. "Well, I get it as much as I can, I guess."

The last of the parade passes by them and the crowd starts to move en masse. They shuffle along with the flow, letting themselves be buffeted down the sidewalk, past groups of singing men and dancing children and pop up tents selling anything and everything with a rainbow on it.

"Thank you," Kate says half a block later, the bottoms of her feet slipping against the insoles of her sandals. "For being understanding."

"What else would I have been?" He asks, tone serious and shoulder bumping against hers. "This is who you are and I love you. All of you."

Her fingers tighten around his, sweaty palms sticking together. "What did I ever do to deserve you?"

Castle laughs, steering them out of the crowd and into a bustling cafe. They get in line to order and he leans down, dropping a kiss to the apple of her cheek.

"Remember when you used to ask yourself that with far less reverent awe?' He asks with chuckle and she rolls her eyes. "I'm glad that's changed. Mostly."

So is she.

So is she.

Thank you for reading. Your thoughts and comments are always appreciated.