His Confession

Feasts at Grimmauld Place with the Noble and Most Ancient House of Black were rather pleasant, if you ignored the death threats thrown across the table, the deadly glares, the drawn wands, the upcoming thoughts of how to kill your sitting neighbours fast and inconspicuously and if you always kept in mind never ever to mention the name of the former heir, now blood-traitor, Sirius Black.
On New Year's Eve 1977 Regulus took all courage he could find within himself and stood up after everyone had finished eating the exquisite dinner the House Elf Kreacher had made.
His father who had been talking to his nephew-in-law Lucius Malfoy raised his hand casually to Malfoy from talking and Narcissa, who was sitting next to her husband, had a weary expression on her beautiful face. He straightened his robe, while his eyes flickered over the faces of his aunt and uncle, his grandparents, especially the knowing gaze of grandfather Arcturus gave him shudders; over to the cold eyes of his own mother and to the nasty smirk on Bellatrix' face.
Before he began to spoke, however, he looked over to the empty seat to his father's left where his older brother was ought to be sitting. But Sirius had betrayed them all and they were not brothers anymore, not even related at all. Blacks had bad blood and Sirius had been the white sheep among the wolves. Regulus wished to be as brave and straightforward as his brother, he wished not to care if he'd disappoint a member of his family or not, but it was too late because he already did. Unless his family Sirius might not have been there for more than two years, though they had shared memories, good as well as bad ones and the older one had always held out his hand to protect him, unless this time.
There were no good words how to start this confession, why did he feel guilty for this at all? It had been his own decision and no one had forced him into this. He swallowed down this awkward feeling and simple said, in a calm and quiet manner "I joined the Dark Lord."
Regulus imagined how his brother would stare at him in shock and how he'd slap him in anger, while screaming at him if he had any idea of what this would guarantee him- a shorter life than he already had in war and if he would enjoy torturing and killing innocent people for the cause of an insane maniac who was not even a pureblood, not like the blood status would seriously matter to Sirius. However, reality was different. There was no Sirius, who could place his hand calmingly on his shoulder to give him strength. Like someone old enough to die he would have to stand this on his own. Yet the emotions on their faces had indeed changed: the eyes of his mother were glinting in joy and with pride, while the face of his father revealed nothing of his thoughts. His cousin Bellatrix cackled in joy and he looked hastily away from her, only to meet the deadly glare of his grandfathers, who were probably the same opinion as his father that it was not the destiny of a pureblood wizard of his family to bow and kneel in front of a half-blood, no matter whose descendant he was. Narcissa instead was merely taking Lucius hand in hers, face free of any sign of emotion.
"Congratulations on that, Regulus", said Lucius with this false, manipulating smile. Uncle Cygnus snorted at this comment and the next second Bella pointed the edge of her wand at her father's chest, who looked coolly at her and literally growled "Lower your wand, daughter."
There was so much loathing in his four words that Regulus shivered.
"It was a good choice, Regulus", reassured Rodolphus Lestrange and made a movement with his hand to admonish Bellatrix.
Indeed it was a good choice, thought Orion at the other side of the table and shared a look with his father. Now the Dark Lord had the heir of the Black family in his hands, which was an incredibly clever move, because the family had might, money and allies whereas Regulus would be safe unless he'd be foolish enough to betray the Dark Lord.