Being the baby sister of Tony Stark would always come with its challenges. But what happens when Tony finds out that Y/N has been dating their parents murderer? Will brotherly love be enough for Tony to accept Bucky Barnes into his family or will Tony's inability to see beyond his own selfish needs threaten to tear him apart from his sister? *Female Reader* *MATURE CONTENT* *BASED OFF MY TIKTOK POV SERIES - LINK IN BIO*