This is most definitely not a good idea.
At the moment, however, that's certainly not stopping him— her— them.
Yes, she thinks, 'them' is probably best word to describe the giant mess of limbs and other various entanglements that they currently are.
The Wahrwalt's dungeon is entirely too huge, undeniably sprawling, and swarming with enemies. Somewhere deep, deep down inside strung up like a Christmas decoration is Halibel, their companion, holding out for a miracle still— and they're on their way to bring it to her, to rescue her, to light her way home to Hueco Mundo at last and end her nightmare with the Quincies.
It's just after a they've wrapped up a large fight against several mid-rank guard units in which he had watched her decapitate a man without a second thought, cold and calculating. The battle ends in a predictably fast fashion as the two former Espada are nearly unmatched masters of combat, and after the conclusion is where this whole 'not a good idea' thing came in.
He has her backed up against the wall, one arm on the small of her back and the other with its hand tangled in her hair. Grimmjow kisses her hard and it's as she's come to expect from him; rough, heavy, and hot. She wiggles around in his grip— trying to protest, to ask him what he's doing, to tell him they need to get moving, but he's clearly not interested in hearing any of it.
When the former sexta finally grants her lips a reprieve for air and Nelliel manages to speak at last, everything comes out in panted fragments.
"Grimmjow— what are you— we have to save Halibel and get out of—"
"Shhhh," she hears in her ear as he plants kisses along her neck, not hesitating to bite and suck on her as he goes so he can leave marks of himself behind. A moment later she hears him mumble against her skin, "God, that was so fucking sexy."
Nelliel blinks twice in confusion and her brow furrows. "What are you talking about?" She asks, her breath still short and face entirely flushed.
"You chopped a guy's whole damn head off." Grimmjow states bluntly before he deliberately sinks his teeth into one section of her neck hard enough to break skin. She yelps in pain at first, but the sound soon transforms a long, languid moan when he begins to kiss and tongue at the fresh wound.
"So what?" She's entirely flustered, not sure why he's doing this to her right here, right now; the neck bites are a weakness for her and he knows that for a fact—
"It was the hottest fucking thing I've ever seen," the former sexta abruptly pulls back to look her straight in the eye and the sheer truth she can identify there makes her shudder. "And then afterwards you went right back to carving up the other guys— you didn't even shake his blood off your blade. That's cold-blooded, woman."
"There is so, so much that is so very deeply wrong with you," Nel remarks in return with a joking smile while she pants, her chest heaving. He grins at her like a madman, his own breath choppy and mangled; he's just as affected by all this as she is, clearly. "But anyway, we have to—"
She stops short when Grimmjow touches his forehead to hers in a strangely intimate gesture and shoots her a handsome smirk that makes her knees feel weak. Not even a second later he's pushed his hips against hers and placed himself in between her legs like he belongs there, settling in comfortably. Nel feels a new wave of heat on her face when she notices him hard against her thigh.
"I want you," he rasps in a low, hoarse voice, and it's so uncharacteristic of him that she's left speechless. "Now. I'm not waiting."
"—We're in the enemy base, Grimmjow!"
"Well then you'll just have to stay quiet, won't you, former tres?"
Nelliel is about to retort when instead she has to hold back an involuntary cry as she feels a single finger dip inside her— his hands must have made their way south without her noticing, as one of them has lazily pulled aside the cloth of her bodysuit at the apex of her thighs. He grinds his thumb in circles against her clit, making a noise of approval when she bucks her hips helplessly in response.
"This is nice," Grimmjow murmurs in a low tone after a few moments, the self-satisfied grin on his face quickly sending additional heat pooling between her legs. "All I have to do is just push it aside, huh?"
It hits her that he's talking about the outfit she's donned for their wartime traipse, courtesy of Urahara. She squeaks as if embarrassed, but he doesn't allow her to feel that way for long; his fingers slowly trace around her, and when Grimmjow comes into contact with her wetness he finds that he has to hold back a noise of his own. He puts his hand back to work at her clit, earning a reaction from her instantly.
While Nelliel lets out small sounds of breathy pleasure and eagerly grinds against him, she can tell that he's moving and shifting beneath her; she hears the distinct sound of a zipper falling and then feels something blunt and hard at her entrance while his fingers continue their work just above.
"Nelliel," he says her name right into her ear, his voice so thick and heavy that she shivers. It's a statement and a question all in one; she responds by reaching for his face and claiming his lips with her own while grinding against him in one smooth motion, granting him silent permission.
After that Grimmjow doesn't hesitate in the slightest to push inside of her, shuddering when he does, whispering her name again in another tone of voice that she can't even begin to describe. He practically hisses when he bottoms out and then remains motionless for just a moment as a sort of courtesy to her; she adjusts herself briefly before squeezing his hips with her thighs as a sign that she's ready.
He's never gentle when he fucks her, and this is no exception; Nel would never be foolish enough to think the Espada whose aspect of death is literal destruction would enjoy slow, sweet, tender love-making. No, Grimmjow has sex like he does literally everything else: it's a battle, a contest, something he has to conquer, dominate, and win.
His pace now, though, is especially bruising and urgent, plunging into her like the world is about to end around them while all sorts of curses fall from his lips. The former sexta is completely relentless, whispering wicked things in her ear while he fucks her so hard she can hardly breathe, can barely think; all that matters in the world right now is him and her and them and this.
Grimmjow doesn't stop with his hands or his words until she climaxes with a muffled cry, biting down hard on his shoulder to stifle the sound. Once he's drawn every last torturous twitch from her body, he resumes his brutal pace with newfound vigor, chasing after his own high this time. Nel reaches out and cups his face with her hands before kissing him, whispering sweetly to him, coaxing him along.
It doesn't take much time at all for the combination of her words and warmth to send him careening over the edge; he lets out a noise akin to a growl when he finishes deep inside of her, resting his head in the dip of her shoulder and shaking.
After they've both spent a few moments catching their breath, Grimmjow pulls out and they go about fixing their clothes as if nothing had happened. Nel stumbles slightly when she goes to walk, her legs still weak— he catches her by the arm and shoots her a shit-eating grin, no doubt enjoying the fact that he's the reason why she's stumbling in the first place.
Her hazel eyes peer out from the alcove in which they had taken refuge, looking around for any guards that may linger nearby. When she doesn't see any, she grabs Gamuza from where it leans against the wall and gestures for him to come join her. He's at her side instantly, Pantera ready in hand.
"You know," Nel says, coming to a sudden realization, "we're probably going to have to do a lot more fighting before we get out of here."
"Oh, I know," Grimmjow drawls with a smirk. "I'll have to tell Urahara how convenient his clothes were in making it so that I could stop you repeatedly along the way."
"I'd break every single one of your limbs."
"Let's cross that bridge when we come to it."