BB!Papyrus/History

For more details, read about the Bad Brother AU here.
=== Pre-SHAETALE/Debut Arc ===
Not much is known about BB's life before the abuse began, or when the abuse began, though it seems to have been present from the beginning. It is assumed the abuse began sometime after Flowey began doing RESETs, or at least that's when the abuse got to its worst. BB, over time, lost more of his loud, cheerful personality and instead became more shy and terrified. He never was confident in himself.
=== Debut ===
BB was kidnapped by Gaster, who had come into his timeline after the latter's studies found this timeline to be suspicious. The skelefam, especially Shae, is able to calm him down and make him feel more relaxed. However, Sans unwittingly scares him, and is ultimately forced to stay hidden, much to Sans's distress. Some time later, with Gaster and Sans in the former's lab, bb comes through the portal, looking for BB, asking Gaster and Sans if they've seen him, angering them both with his insults towards BB.
After an altercation with the gang, bb is about to force BB to come back home, when Shae angrily accuses him of never loving BB. BB, in denial, is about to correct her when bb confirms this to be true. Heartbroken and in despair, BB realizes he can never make bb happy while he's alive, so he tears out his own SOUL from his ribcage, about to commit suicide. However, Shae helps step him down from it. After being talked down, he promptly faints from the pain and blood loss. While he's recovering, Shae, Nick, and Papyrus stay by him in the latter's room.
When he wakes up, everyone is relieved and comfort him as best as they can. Daniel them offers him a place to stay, in which he accepts, with Nick's encouragement.