Regrets.
Regulus doesn't remember his first word, he does remember however, was when he asked Sirius what it was.
"Siri? What was my first word?" Little 8 year old regulus had asked curiously, Narcissa's first word was brought up earlier while they were all in Sirius' room. (it was "shit", repeated after Andy)
Later, after his 3 cousins left, Regulus got curious about his first word.
"You said my name! Well part of it-" 9 year old Sirius exclaimed excitedly.
Sirius smile was so bright then, Regulus wished he was that bright.
Regulus sat in Sirius old bed at the Potters, not knowing what to do. All his mind could come up with is memories, memories, fucking memories.
"Sirius! Why can't you just do what they ask?!" Regulus hissed, he was 13 and had pulled Sirius into his room.
Sirius had a red hand print across his cheek, but he refused to cry. He rolled his eyes, "Maybe i don't want to play by their stupid rules!" Sirius said, a little to loudly.
Regulus roughly put his hand over his brothers mouth, he pulled out his wand and casted a silencing charm on his room. Something he often did to block out the screams.
"Sirius their going to ask you to take the mark in 2 years you can't be doing this!" Regulus snapped.
Sirius gritted his teeth and shoved Regulus' hand off his face, "Did it ever occur to you that i don't want to be someones dead fucking deatheater?!" He basically yelled.
It had stopped Regulus in his tracks, of course it hasn't occurred to him. Why would it? What else would Sirius be?
"That's what happens when you follow them blindly Reg! You join them, and you end up dead in a cave!" Sirius snapped, and then stormed out of Regulus' room.
That was before Regulus learned he could get out of this house. That was before he understood Sirius more.
That was before he had felt the true ache of missing his brother.
"You like him?" Sirius randomly popped out of no where. it was 4th year at Hogwarts, they weren't talking much anymore. Regulus never expected him to speak up, especially about that.
"None of your business" Regulus hissed back. Why was he asking?
"Hey! I'm not judging, i was just wondering, cause a little birdie told me he might feel the same." He whispered, Regulus of course hides his face and blushs red.
"Well, do what you got to do little reggie" Sirius said, and he left as easily as he came.
"What are you thinking about?" Came Remus' gentle voice. Ah yes, the him.
"Nothing" Regulus murmured, that was one of Remus' best friends and he was worried about Regulus.
Remus slid his hand under Regulus' and intertwined their hands. Regulus, obviously, looked away to hide his blush. He wasn't really used to physical contact like this, what was he supposed to do???
Regulus regrets a lot of things, not talking to Remus sooner, the family he was born into, going back to grimmauld.
But most of all.
Not realizing how much he missed his brother sooner.