AITB for confronting my stepsister to catch her in a lie?
my stepsister “Rose” F14 is a manipulator she has bragged to my mom about being a manipulator and how she used to cry to get her way. she has a huge history of lying, making up stories to her dad that people hit her when she doesn't get her way, even used makeup before… and spreading rumors at school her school about our stepbrother and my cousin Josh (which is brock’s brother) saying he has STDs and does drugs (she denied it), rose like to compete with others based on achievements and she likes to be in control and gets upset when anything gets in the way of her unadulterated want to control and dominate. recently, rose told me our cousin Brock M13 told her that he came out as gay to our gma, and that grandma didn’t care. the issue is, our grandma is deeply homophobic.
I M16 felt like that was weird because Brock doesn't talk like that, I asked him directly. he told me it was a lie and he hadn’t even spoken to rose in a while. I realized roses motive was probably to get me to casually bring it up to gma, which would’ve outed brock
so, when we were all hanging out, I asked brock out loud how he was doing with his friend, and then asked, "wait, rose told me you came out to gma, is that true?"
rose immediately began gaslighting me. 1st she tried to shift the blame to josh "I said JOSH told me that!" i know that’s isn’t true because when she first told me the rumor weeks ago, my immediate internal reaction was (why would Brock tell her and not me?) If she had actually mentioned Josh’s name back then, I would've been mad at him, just naturally, bc i don’t like that outing people thing. especially your brother. If i’m not delusional or crazy this is what she said “you didn’t know? yeah, brock came out to grandma but she said she didn’t care, but he told me not to tell anybody”. obviously not verbatim but on that track.
then she twisted it again, claiming Josh told her *and* his girlfriend that Brock was gay and said "don't tell nobody." But right then and there, Alonte texted his girlfriend to check, and she said he never said that. his gf also spoke up and said that conversation never happened.
then she started saying things like "how can you tell me what i said” and “i know what i said” “what would i have to lie for?” that I misheard her, and that what she said is "fact." but then our cousin gianna (F16) called her out for changing her story, so rose was like, "well, I don't know if it was josh or his gf, but it came from josh."
at the end of that, I just looked at her and said “the moral of the story is don't talk about my cousins, and don't repeat anything unless you go up to them with it to confirm." now she’s acting weird and trying to play the victim like we "ganged up" on her. AITAH for trapping her in her own lie?