Oh, my God.

For one brief, tense moment, Mycroft didn't think Sherlock would do it. The nipple play they'd indulged in downstairs was not unprecedented: the summer that he turned six, Sherlock had delighted in catching Mycroft shirtless and giving him painful 'tit twists'. Even the spanking was nothing new- after their father died and their mother became too overwhelmed to handle her wild younger son, Mycroft had administered well-deserved punishment to Sherlock… whenever he could catch him.

There was no precedent for the slick, cool fingers that suddenly slid between his cheeks and probed carefully at his entrance.

Mycroft knew that both of them were watching him closely, ready to stop the scene if they detected discomfort or anxiety. To his surprise, he felt none. Let go. Ordinary boundaries don't exist here. All that matters is whether it feels good. And God, it does.

Sherlock pushed in with one finger, withdrawing to insert more lube when he detected tightness or friction. He pumped the finger straight in and out, finding Mycroft's prostate on the first go. The elder Holmes groaned and tilted his hips, wordlessly pleading for more.

"You look fucking hot," Gregory groaned. "Both of you. Tell him what he needs to do, Myc, to make you feel good. He's here to learn."

Mycroft could find no fault, and said so. "He's doing just fine. Perfect, in fact."

He sensed rather than saw his brother's smile.

Sherlock now had three fingers buried in him to the knuckle, each slow and patient inward thrust giving his prostate the absolute maximum pleasure. The muscle stretch was slightly painful, though: when Mycroft winced but refused to complain, Gregory climbed onto the bed and offered him a favorite distraction: his cock.

"Oh, Greg," he moaned before leaning forward and running his tongue along the underside of Greg's shaft. He closed his warm, wet lips around the salty head in a reverent kiss, savoring the taste. While Sherlock carried on with opening him up for this very treasure, Mycroft took it deeper into his mouth until his nose touched pubic hair and Gregory's balls tapped his chin. Relaxing his throat muscles, he bobbed his head with the quick yet smooth motion that drove Lestrade crazy.

Gloved fingers buried themselves in his hair. "Fuck… incredible… but slower, love, or you'll have me off before I can take your beautiful arse."

"I think he's ready," Sherlock said.

Lestrade carefully drew his shaft out of Mycroft's mouth and removed his trousers. Mycroft sighed in anticipation as Gregory pulled him onto his left side and spooned up behind him.

"Raise your right leg a bit, Myc," he said throatily. When Mycroft obeyed, Lestrade took the lube bottle from Sherlock, thoroughly slicked himself up, and began pushing his cock between Mycroft's cheeks. As he felt it slide into his body, the elder Holmes cried out and clenched his fists.

"Easy, easy. You OK?" Lestrade stopped immediately and caressed his hip.

"Yes, yes." Mycroft licked his lips and took deep, ragged breaths. "So intense. Feels marvelous. Keep going."

Gregory pressed inward until his prick was completely buried in Mycroft's still-tight passage. Despite Sherlock's careful preparation and the shag session with Irene downstairs, Mycroft experienced a stretch and burn that made him feel full and warm and sweetly violated. He trembled and his sphincter clenched, drawing an ecstatic moan from Lestrade.

"Tight. God, you're so tight."

He reached down and gave Mycroft's rigid cock a few slow, sensual tugs. Mycroft arched into the touch, feeling himself relax enough to let Lestrade wriggle his hips experimentally. The hard shaft buried inside him brushed over his prostate, nearly sending him off the mattress. Only his bound wrists and Gregory's firm embrace kept him in place.

"Now! Fuck me now!" he begged.

Lestrade wrapped his arms around Mycroft's chest and began riding him hard. Mycroft pushed his hips backwards and whimpered, both demanding and begging for deeper penetration at the same time. Gregory kissed and bit at the flesh below his collar and whispered, "Want more, Myc? Tell me what it is you want."

"You. Faster. Harder!"

Lestrade rolled them both over and got up on his knees, pulling Mycroft up on all fours. Gripping hard enough to leave future bruises, he pounded into his lover, ramming his stiff length repeatedly into that impossibly tight hole. Each inward thrust nearly sent Mycroft flying against the headboard.

"Ugh! God, Greg! So good!"

"You love cock, don't you? You love being stuffed with it until you can't feel anything else."

"Yes! Yes."

Lestrade paused and leaned over Mycroft's sweaty back until his lips were only inches from his ear.

"Think this tight and greedy hole could take your brother and I at the same time?"