In most areas of his life, Michael was calm, confident, and naturally in charge. Nothing shook him, and few questioned his command. But, when the door was locked and he was naked, that all changed.

In bed, Michael was very chaste, and modest…Hell, he was down-right shy. He would blush, stammer, and hide his face as best he could. He did whatever he was told, and his begging was always loud and broken, tongue stumbling over the filthy pleas. He turned scarlet whenever Lucifer winked and licked his lips, passing him by in the halls during the day. Because he knew what that look meant. Because he knew what those eyes and that mouth were promising. "L-Luce!" He stammered, as his younger brother pushed him roughly against the wall. "Please, don't tease me anymore…" He spread his legs in invitation, hoping his brother would unzip his jeans and give him what he needed. Lucifer pressed closer, grinning wickedly. "What do you want me to do to you, Michael?" He whispered. Michael's blush returned, a soft pink creeping up his cheeks. Lucifer pressed his hips to Michael's, rocking against him a few times, to show he was hard too. Michael moaned, and grabbed Lucifer's broad shoulders, rutting against him. He actually loved doing it this way, though he'd never admit out loud. It was so rushed, so dirty. Lucifer's hands tightened on his upper arms, and he kissed Michael. Softly, reverently, promising just as much love and tenderness as cruelty. His hips stilled, and Michael cried out against his lips. "Lucifer no! It was so good, don't stop!" Lucifer dragged his hands slowly along Michael's arms, pausing at his wrists. He gently removed Michael's hands from his shoulders, and pinned them over his head. "Luce…" He whined.
"Shh, baby, don't fuss." He said. "What do you want me to do to you?"
"I, I, oh don't make me say it! Just, what you always do, please!" Lucifer shook his head. "Uh-uh Mikey. Gotta be specific. Tell me exactly what you what me to do. Exactly what parts you want me to do it to. How hard. Go on baby. Nothing to be ashamed of. Just say it. Just tell me." Michael closed his eyes, face crimson now, heart fluttering. "Why do you make me talk dirty?" He whispered.
"I like the colors you turn. I like how you squirm while you beg. And, most of all, I like hearing what you like. What you're in the mood for. That I'm doing a good job." Lucifer kissed him again, and ground his hips a little. Michael took a deep breath. He could use his safe word, he knew that. He didn't have to say anything filthy if he really, really didn't want to. But, Lucifer thought this was good for him. Good for making him less ashamed of what they did together. "Nothing wrong with it, baby." Lucifer had panted into his ear, that very first night. "Nothing at all, it's natural, it's beautiful, you're beautiful, fuck Michael, you're so tight…"
"I, I want you to…"
"Yes?" Lucifer's kisses had moved to his neck. Gentle and nurturing. "I want you to stroke my cock." Michael managed.
"You wanna fuck my fist, big brother?"
"Oh, oh yes, I do, please."
"And then?"
"Luce!"
"Keep going Michael." He ordered. "I told you to be specific. Don't make me have to spank you."
"But…but I want to be spanked." Michael whispered, closing his eyes tightly. Lucifer was silent for a second. "Really now?" He breathed against the shell of Michael's ear.
"I want you to stroke my cock, m-make me cum for you, and th-then put me over…" He paused and swallowed hard. "Put me over your knee, and smack my ass. Hard, until, until I beg. Until I'm hard again."
"After that? After that Michael? Want me to leave you hard?"
"No! No, no, I want you to put me on my back, and make me spread my legs."
"You look so good like that."
"And I want you to, to lick me."
"Lick you? Lick you where?" Lucifer was holding Michael's arms in place with one hand now. His other hand was rubbing Michael's chest through his shirt. Stroking down over his firm, hard stomach, to play with the button of his jeans. "Lick your stomach? Your thighs?" Michael shivered. "Your cock?"
"No. My, my, my hole." He forced out, redder than either of them thought possible, but it was all worth to hear Lucifer's sharp intake of breath. "Oh? You like that, huh? Like it when I rim you?"
"Yes, I love it, I love it so much." He moaned. "And, I want to cum again, from that. I want you to make me filthy." Lucifer answered with a low growl, and undid Michael's fly. He pushed down his jeans and briefs one handed, and gave his beautiful baby what he wanted. He wrapped his hand around Michael's cock and stroked him roughly. "And then Michael? Because you know I'm not finished with you." Michael no longer avoided Lucifer's eyes. He gazed up at him as his blush lessened. "I want you to finger me. I want you to take you time, get me ready for you. I want to squirm and whine and wiggle on your fingers. I want you to rub my prostate and tease me all you like because it's good, it's so, so good." Lucifer kissed him, hard and rough. "Okay baby, I think I got the picture." He panted, still jacking Michael's cock, twisting on the upstroke. "What else baby? Anything else?"
"I want to you fuck me. I want you drive in, all at once, as deep as you can go as fast as you can. I want you to hold me down and make me take every last inch. I want to be pinned down while you thrust in and out, want to feel you use me like a whore, like a toy. I want you to call me 'baby' and 'big brother' while I lay there helpless because it's so good I can't even move, can't think, can't even breathe. I want you to fuck orgasm after orgasm out of me until I'm screaming. And when you're satisfied, when you're done with me, I want you to cum inside me. And I want you to kiss me. Tell me what a good boy I've been. Clean me up gently, and tuck me into bed. Kiss my forehead, and stroke my hair until I pass out." Lucifer was smiling at him, eyes full of love and lust and something like awe. "I want you to take care of me, Luce." He added softly, before thrusting up into Lucifer's now still hand. "Pretty, pretty please?"