You thought Regulus was dead. You were sure of it.
You and him were best friends from 2nd year to 7th. He was a quiet kid, who rarely ever talked, unless to you. You were a loud girl, extroverted, and quite talkative. He was Slytherin, you were Gryffindor. He was pureblood, you were muggleborn. And he was a death eater. You had no idea, though.
Shortly before he died, he distanced himself from you. You couldn't understand why. You were one of his only friends, other than Barty and Evan. But it seemed he was distancing from only you. It was weird.
As soon as you found out he passed away, trying to defeat the dark lord, destroying one of his horcrux's, you were devastated. He was one of the only friends you trusted fully. And you cared for him dearly. For almost 2 weeks, you could barely get out of bed. But after you got over that stage, you came to the black lake every day, where he died. You made a little thing for him. You had put a picture up of him, and every day you would bring a different thing to put by it. Almost like a tomb, since he had drowned, so he couldn't be buried.
But one day, you were sure your eyes were playing tricks on you. It had been 3 months since he had died, and yet you could spot that curly black hair anywhere. He was behind a tree, waving you over. Not sure if you were hallucinating, you got up hesitantly. Once you were sure he was real, you ran towards him, hugging him tightly. Regulus was unfamiliar with affection. After all, the blacks were not very affectionate people. But after a moment, he wrapped his arms around you too, loosely.
See, in his perspective, he had to fake the death. He was raised thinking that every muggleborn was horrible. But once he met you, he knew they weren't bad. So becoming a death eater was harder for him. But he couldn't escape his fate. So he had to fake his death. Otherwise he'd be stuck as a death eater, a murderer. But how was he supposed to explain all that to you?