Just_A_TM_Fan (Ao3) prompt: It's pre-relationship and that during one of the arguments, Usagi tells Mamoru that he's too boring to ever be good at 'having relations' and Mamoru takes that as a challenge and dares Usagi to come to his apartment, so he can prove her wrong, and if she wins, he'll buy her milkshakes for the next week, but if he wins, Usagi has a to wear a t-shirt that says "Chiba Mamoru is a sex god."

Blueeyeddevil06, thank you for being my beta!

"You complicated twit!"

"Did you just call me a twit?" Mamoru looked at her and began laughing. "Twit?"

"Ugh! That's what you are!" Usagi stomped her foot in annoyance.

"You're acting childish again."

Usagi rolled her eyes, "At least I have a personality!"

"Yes, one of a five-year-old that hasn't gotten her way," he smirked back.

"I'm passionate. You don't even know what that word means. Your personality is so lacking. I bet you suck at sex. You wouldn't know how to let go. It would be boring. I bet a girl could fall asleep during sex with you."

Mamoru's eyes flashed dangerously. He pulled Usagi to him and growled out, "I dare you. Come to my apartment. If you're right, I'll buy you milkshakes for a week. If I make you scream in pleasure, you wear a shirt that says, 'Chiba Mamoru is a sex god.'"

She scoffed, "Fine. Just promise to wake me up when you're done."

He rushed them home. He was pissed, and he wanted to prove to her that he could make her scream his name. He didn't even stop to think why it meant so much to him.

He pressed her against the wall once they were in his apartment, and he kissed her passionately.

All Usagi could think was, "Shit, I'm going to have to wear that fucking shirt." She was glad he was kissing her, and she couldn't slip and say that out loud.

Mamoru broke the kiss and pulled off her shirt. His eyes blew wide. Her breasts were huge and - perfect. He pulled down the cups of her bra and pinched her nipples.

He heard her suck in a breath, and he looked at her face, and she was biting her lower lip. "Oh no, that's cheating." He pinched her nipples again. "You can't keep yourself from screaming out in pleasure."

"You wish!" She shot back.

He fumbled with her bra and got it off. He then went back to her breasts. "Oh sweet, little Usagi-chan, you're playing a game you can't win." He pressed her against the wall and whispered huskily in her ear, "I'm going to make you scream my name."

He then pulled her forward by the hand and brought her to his room. He laid her out on his bed and removed the rest of her clothes. "And now it's time for the real fun. I'm going to drive you wild."

He spread her legs and kissed her stomach. She gasped out while he trailed his tongue around her navel and then nibbled her stomach. He then kissed a path down towards the very core of her. He pinned her legs down then licked between her already wet folds.

He flicked his eyes up to her and chuckled. "It seems like your body is calling you a liar. You're so wet for me already. You wanted me like this, between your thighs. Didn't you?"

"You wish!"

"You need a new comeback. That one's getting old." He smirked and then flicked her clit suddenly with his tongue. She moaned out loudly in pleasure.

"Seems like your whole body is calling you a liar. Your nipples are so hard right now. You're wet and moaning for me. Wait until I really get going. You're going to fucking love this." He then licked her again and sighed, "You taste so sweet."

"You're enjoying this," Usagi shot back. "This was all an excuse to fuck me, wasn't it? You argue with me all the time, but really, you just want to be buried inside me."

Instead of answering, he slid one finger inside of her and sucked on her clit. She moaned lustily and arched her back. He then added another finger and started fucking her with them. He then began playing with her clit with his tongue.

By the time he brought her to orgasm, she was fisting the sheets, arching her back, and screaming out his name in ecstasy. He sat back on his bed and gave her a shit-eating grin. "I haven't even fucked you with my cock yet, and you already lost, Usa."

She glared at him as he got up, removed his clothes, and rolled a condom on his huge cock. She hated to admit it. She was impressed. She knew she wouldn't tell him.

"Now," he said, making his way to her, "It's time for the best part. I'm going to watch you lose your mind when I fuck you, Odango."

"We'll see." She flicked her eyes to his cock, "So far, I'm not impressed."

He laughed at that. "I saw your face when I pulled it out. You lie."

"You wish!"

He laughed at her. "I thought you were going to come up with a better comeback." He stroked his cock. "You're impressed, and in a minute, you're going to be wild underneath me. I felt how tight you are. My huge cock is going to feel so good for you in your tight little cunt. I'm going to fill you all up and make you scream."

He then laid over her and thrust into her. "Fuck!" He roared. He was damn glad he put on a condom. He knew he could last longer with it on, and right now, he wanted to shoot off like a rocket. He hissed through his teeth. She was already such a good, tight fuck.

Once he got himself under control a bit, he pulled almost all the way out and thrust back into her hard. She moaned, and he smiled. He was going to be able to get her to go wild. He grabbed her hair, tugged it a bit, and bared her neck to him. He then started taking her with deep, powerful thrusts intended to stimulate her and drive her wild.

He loved the feeling of her breasts jiggling under him while his hips snapped hard, impaling her with his cock. He then heard her screaming wildly and grabbing his ass. She dug her nails into him, and it fed the fire of desire deep in his gut.

She bit his shoulder, triggering his orgasm and taking her along with him. Her walls fluttered and milked him dry.

He collapsed next to her and struggled to get his breath back. Once he did, he smirked and said, "I can't wait to see you in that t-shirt, Odango."

She glared at him while she panted for breath. "Don't call me Odango."

"Fine, how about Usako?"

She looked at him in surprise, "What?"

"Don't lie to me. You can't have sex with me like that and pretend you don't have feelings for me afterward. I knew how you felt from the moment you kissed me."

"You kissed me!" She argued back.

He gave her a wry smile, "I know, Usako. I did."

"Admit it first!" She shot back nervously.

"Usako, I love arguing with you. But all it does is leave me frustrated and turned on afterward. You're the most stimulating woman I know."

"It turns you on, Mamo-Chan?"

He smiled at her, "It does. Can you honestly say you don't feel the same way?"

"I just figured it was only me."

He shook his head, "I dared you to have sex with me, Usako. Trust me, I wanted to. Desperately. I figured it was my chance to convince you to be in a relationship with me."

"Well, it turns out it worked. You fucked me into agreeing to date you."

"Works for me." He smiled and pulled her to him. "Although I'm about to dare you to have sex with me again."

The next day, Mamoru had a massive smile on his face when Usagi walked into the arcade wearing a shirt that read, "Chiba Mamoru is a sex god" across her ample and love bitten chest.