A/N: Fuck it why not part three for all ya robotfuckers

It was strange at first to have him hold you like that, but as he pulled you around and introduced you to the other monsters there, you became more okay with it. It was still awkward for you, as you had been hating on this guy 48 hours prior.

"Darling, what's wrong?" Mettaton asked after you had met everyone, "Are you upset about being here?"

"No, no, it's actually pretty great being here with you. The only thing is that I feel bad."

"Why is that?"

"It's really nothing, Mettaton."

He grabbed your hand and pulled you to a different, empty room and stood with you in the far corner.

"Tell me what it is, darling, I'll listen."

You sighed,  "Well, I'm worried because we're already acting so coupley so soon. Like, what if tomorrow we decide this is a one day thing?"

"It has never been a one day thing for me. When I fought you in the underground, I really hoped you would stay with me. I knew you wouldn't, but I still wanted you to. The only issue is if you don't feel it."

"That's what worries me, Mettaton. I'm scared that this is just the result of the sleepover and having some fun with you. I think I liked you all along, but I'm scared that I didn't."

"Well, if that is what the outcome is, I will personally tell everyone that it was my fault. But please, just for today, even if you don't feel anything, be my girlfriend," he requested.

You sighed and placed your hands on his chest, "Okay. No matter what tomorrow brings, today first."

"Fabulous!" He pecked your forehead and you two left the room, still hand in hand.

At some point during the gathering, Mettaton has become separates from you. Of course it was so he could dote on Blooky, but you had no problems. It was then that Alphys approached you.

"(Y/N), w-what h-happened? I thought y-you hated M-Mettaton," she asked.

"Yeah, Alphy. I actually did like him. I liked him a lot. And now we're a thing. Why, is there something wrong with that?"

"N-no! I w-was just w-worried that he was f-forcing you."

"Not at all, Alphy. He's actually pretty great. Good job with him."

Mettaton must have noticed you talking because he came over to you and Alphys.

"What were you two talking about? Gossiping?" He asked, standing by your side.

"No, I-I was just t-telling (Y/N) how g-glad I am that she f-finally let you h-have a chance w-with her. You always w-were talking about h-her," Alphys responded.

"Is that true?" You asked.

"Completely. Right M-Mettaton?"

"Yes doctor, it's true," Mettaton sheepishly said. You looked at him and he was flushed bright red.  You giggled and linked your fingers with his own.

"It's fine, Met. I like it."

Hours later, the party goers decided that it was time to go.  The cried dispersed, leaving only you and Mettaton, Alphy, and Blooky.

"Mettaton, D-do you want me to t-take you h-home?" Alphys offered.

"No, its fine. I left my car over at (Y/N)'s place anyway. I'll see you all, and thank you so much, darlings."

When you got in your car, you sighed heavily, "It is finished."

"Lets get to your house safely, them we can call it a day."

You made it home easily, unlocking the side upon entry.

"So, um, I guess goodnight?"you half-heartedly suggested.

"Should kiss you bye?" Mettaton asked.

"Sure," you smiled as he leaned down to your height and placed his lips full on your own.

You hadn't expected such a bold kiss, but you rather liked it. You pressed back against him, snaking a hand through his black locks.

In fact, you may have enjoyed the kiss too much, as you turned a simple kiss into a rather passionate one.  Still gripping his hair tightly, you pressed your tongue against his lips. Mettaton, as forward as usual, stepped into the house and allowed you to close the front door. You did so and promptly continued the kiss, delving your tongue into his mouth. The two of you stumbled backwards as you wrestled for dominancs. You eventually hit the couch and fell on to the cushions.

You repositioned yourself to that instead of awkwardly laying on him, you sat on his lap. He sat up and continued to kiss you.

His tongue delved in deep your throat, and he obviously won the competition of domination. His arms wrapped around your back and he began to slip a hand under your shirt. You felt it but let him do as he pleased.

You began to grind on him as he kissed you. At this point, any good judgement was gone. This robot had awakened the lust in you and turned you on like no previous fling. You couldn't help but to moan slightly at the feeling of your pussy rubbing on him.

You pulled back from your liplock to ask, "Can you feel that?"

You bit your lip and grinded on him again for good measure.

"No, not very well. But I have sensitivity meters, I can turn it up if you're sure you're ready for where we're heading."

"I'm not sure if I'm ready but goddamn do j want it," you told him. He laughed at your bold statement and reached for a hidden dial somewhere. You heard a few clicks and then he nodded.

"Did it," he grunted.

You kissed him again and grinded harder on his crotch, enjoying how he now grunted and squirmed. You whimpered slightly at the friction as well.

He tugged on the hem of your shirt. "Off." was all he could gasp out. You interpreted his request and pulled off your shirt, tossing it to the floor beside you. He groped at your breasts, showering you with complements and kissing along your cleavage.

"You could just do that, or you could take off my fucking bra and actually see them," you told him. He chuckled lustfully and positioned his hands at your back.

"This isn't my first time, darling. Trust me, I know what I'm doing. But, if you insist, how can I refuse?"

In one swift movement he unclasped your bra and took it off of you, freeing your breasts from their constraints.

You bounced on his crotch purposely to make your chest bounce along with it. It also made your throbbing pussy even wetter.

"Too tempting," he whispered, capturing your breast in his mouth. He kept you straddling him as he rose up to nearly press his face against your chest. He sucked on your nipples, making them stand pink and erect. You released quiet moans as he continued his ministrations on your chest.

You had your eyes closed and your hands in his hair when he flipped and moved so that you were under him. Fluidly, he hooked his index fingers in your panties and jeans and slid them off, sending his white gloves with them.

When he saw your pink, throbbing, soaking core, his eyes lit up and he pressed his thumb to your clit. You couldn't help but to breathe in sharply as he continued to rub the sensitive tissue. You attempted to press against his hand even more.

But the real pleasure began when all at once he shoved three of his fingers into your pussy. You whimpered and arched your back slightly as he began to slowly pump them in and out. The juices covering your vagina were enough to ensure he moved smoothly.

You became impatient with his slow actions and pleaded, "More... Please... Oh do it harder, for fucks sake!"

He complied with your wishes and immediately changed the pace of his movements, rapidly driving his fingers into you.

You bucked your hips against his hand, moaning aloud and breathing sloppily. You could feel yourself coming to the edge when he stopped.

You opened your closed tight eyes to see a huge glowing pink dick emerging from his crotch. One thing worried you, it looked far too big.

"Mettaton, I don't think you'll fit," you voiced your worry.

"Don't worry darling," he assured you, "I'll make it fit."

And with one fluid movement and a scream of pain, he was inside you.

You panted as you tried to adjust to his long size, and he waited for you. As soon as you thought you were ready, you nodded at him and said, "Fuck me hard."

He pulled his length all the way out and slammed it back in, and you moaned in partial pain and pleasure. However, as he kept going your moans were exclusively pleasure, and he was grunting with each thrust.

A few minutes of him fucking you and he hit just right, penetrating your g spot. You cried out loud in pleasure, clenching your bare legs around his waist. Every subsequent thrust hit that spot, and each time you grew closer and closer to the edge.
As you both neared your orgasms, he stuck two fingers into your asshole without warning. This was enough to send you over the edge, cumming all his dick.

As your pussy clenched around it, he came inside of you, and it was of course pink. The two of you laid there for a whil3, catching your breath.

After a while, you spoke, "Mettaton, we just fucked. On my couch..On your birthday."

"Yes?"

"You had birthday sex on my couch. Can we just appreciate that for a second?"

He laughed at you, "Well, I don't know about your previous doubts, but this seems like the making of a wonderful relationship. Now, let me help you get cleaned up."

Edit: Holy shit this is bad, I might go back and do an eensey bit of editing
And by eensey I mean change the whole fucking thing