A little head ups, this isn't gonna be part of my timeline, it's just an experiment with this particular idea of my friend :)

If you also read our ZEXAL lemon collab (YumaxKotorixCathyxRio), same warnings apply: It's more adult tham my other lemons. I'm not very used of these things so I tried to not overdo too much, also I tried to lean slightly towards Hamm's style, so I'm using some explicit words here and there, but not too many.

I hope you enjoy.

Yuya went to the door, hearing someone ringing. Curious that they came just as his parents went shopping.

He was surprised to see Lulu Obsidian. Also surprising was that she was strangely alone.

«Hi Lulu. Where is Shay? Usually he's with you when you come visiting Yuto.»

The purplish-black head gave a uncharacteristical grin. «Well, he had other... matters to mind, so I came to spent some... personal time with my Yuto, if you don't mind, Yuya~.» she said sweetly.

Yuya blushed slightly and rubbed his head. She was too dangerously similar to Zuzu for his likes. «Oh yeah, no probs! I'll let him come out.»

Yuya closed his eyes and a flash of violet light enveloped him, and when it died down, the Xyz Bracelet Girl was overjoyed to see her beloved Yuto standing again in front of her, complete with a darker version of Yuya's current robes.

Lulu quickly threw herself into his arms and nuzzled his neck, much to his (and Yuya's) shock. With a stealthy kick, she pushed the door closed, and started tracing his face with her fingertip. «I miss you so much... having to cross dimensions every time I do, and having Shay eagle-eyeing me to boot, is driving me crazy...» whispered Lulu in a tone that was unheard of to Yuto, but very much familiar for Yuya.

«Having been frozen on the chaste date stage since...» she looked down for a moment before staring again in the gray eyes. «...the war... I-I want, and I need the next steps! Please Yuto!» The Xyz Yu glanced up to the Standard one with a terrified look. «What do I do?» asked telepathically the former. Yuya looked down at him with a sly grin. «What she wants. The dirty stuff.» he answered, air quoting the word "dirty" with his transparent fingers.

Yuto paled up a bit as Lulu gently grabbed his chin and brought their lips together. As much as Yuto was incapable of resisting her, he still tried to talk with his host. «But what will Zuzu do when she will know that we're doing that sort of things with your body?!» Yuya licked his lips. «I don't mind, because she will never know.»

Suddenly Lulu's kiss became much hungrier, completely pulling Yuto's attention to her. The boy timidly grabbed her arms to pull her closer, but she was already much ahead. Without warning she guided him backwards before throwing him on the sofa, and pinning him on it. Yuto's face was scarlet as he and Lulu respired each other's breaths. «Yuuutooo~...» she slurred sultry, «...I really, really feel needy, and I want you to... quench my desire...» she untied a string which made her sundress fall off, revealing that she wore nothing whatsoever under it.

«Please, Yuto...» she pleaded. She had always been the adventurous one in their relationship, but she would never dream to do something that he didn't want. «Take me.» At least as long as she was in control of what she did...

Yuto seemed distraught for a few seconds, before he calmed down and rubbed her cheek. «Uhm, o-okay.» His hand carefully grazed drown her neck as her eyes fluttered closed. He then moved it over her collarbone, and after a moment of hesitation, firmly groped one of her breasts, causing her to let out a moan.

Yuto froze again as she looked down at him with a lustful gaze. «Wow Yuto, that was unusually straight-forward for you. Is Yuya advising you?» she asked with a wink. Yuto smiled awkwardly. «Uhm, yeah.» Lulu smiled as well. «Of course, his experience with Zuzu is gold, isn't it?» «Yeah...» «Alright then, now please, keep going!»

Yuto nodded as he followed Yuya's suggestion and knead both of her boobs, making her moan in a way Yuto would have never imagined. «Yuto! You're doing really good! Please... finger me! I'm already wet enough!» Blushing even harder, Yuto complied her request and trailed one of his hands down her belly, and very gently caressed his middle and ring fingers against her pussy, making her wheeze in pleasure. «Y-yuto! Ins-side...!» Encouraged by her beautiful sounds, Yuto obeyed again and pushed the fingers between the labia, then began pumping them in and out while at the same time rubbing against her clitoris, as told by the Standard counterpart. Lulu screamed in ecstasy. «Oh my god! I was right, your fingers are so much better than mine!» Yuto almost choked as he tried to shoo away the sudden, dangerous fantasies of his girlfriend alone in the darkness of her bedroom, masturbating as she moaned his name in longing.

After a bit Lulu threw her head back and cried. «Yuto, I'M CUMMING!» Sure enough, Yuya and Yuto felt her fluids splashing on their fingers and she slumped over them, panting. «Well,» she murmured breathy, «I guess I owe you now~.» she winked as she pulled down their pants and grasped their stiff dick, earning Yuto's moan. Lulu smirked as she slid back until she was looking at their throbbing crotch. «It looks so tense.» she teased as she delicately rubbed it, yet enough to have Yuto turn into a blubbering and moaning mess. Giggling for herself, she lowered her head and brushed her tongue against their cock, causing both of them to gasp this time.

«Holy shit, is she gonna suck there?! Zuzu never did that!» exclaimed Yuya in surprise. Yuto couldn't really hear him, since Lulu immediately went all-out and was running her tongue all over his shaft. «L-lulu! Lulu! Luluuuu!» the only thing Yuto could do was chanting her name mindlessly, the sensation was just too blindingly powerful for him to think of anything else but her, and her wonderful mouth. His hands were balled into tight firsts around the cover of the sofa, so tight the skin was turning red. Lulu gave him a particularly long and throughout lick and Yuto cried as his hips jerked despite trying to control himself. «C-coming! GAH!» He threw his head back on a pillow as his cum sprayed on Lulu's face, which she quickly wiped away with her hand.

As Yuto tried to catch his breath laying back, he watched the girl sitting up on his belly, gently beginning to fondle herself. «Lulu, what are you doing?» Lulu smiled sweetly to him, pinched her nipple with one hand and spread her pussy with the other. «Oh, just getting both of us in the mood for the finale~.» she teased as she soon felt the erection poking her ass. «Are you ready Yuto? I promise it won't happen until you say so.» she asked to be sure he was fine. The gray-eyed boy gulped.

«I... yes...» he whispered, leaning up a bit to share a kiss with his beloved. While she met him, Lulu lined up her pussy with his cock, and was just about to lower herself, to relieve months of pent up frustration due to her boyfriend's awkward situation preventing this kind of thing until now, but...

«Hey, Yuya, are you here?» The door suddenly opened to show Zuzu. Her eyes immediately went blank as she set sight on the two mating lovers, one of whom was borrowing her own boyfriend's body. An awkward situation indeed.

So awkward Yuto more or less died of embarrassment and vanquished, slamming Yuya back in his place, just a millimeter from penetrating Lulu.

This was gonna need so many explanations.

The second part is gonna is be posted by my friend in a while, so please don't ask me for the follow-up ;)