AITA For Telling My Brother His New Girlfriend is Inappropriate For a 12 YO?

My brother is 28, he has a 12 year old daughter. No one knows who her bio dad is and my brother has been a single parent ever since she was born. <br><br>She is a very mature young girl, not your average preteen girl, she is very smart, has a mature sense of humor, and she’s not into kids stuff, she likes to read a lot and listen to music, she’s into rock and metal, not the average kids stuff. She’s very much into being a teenager but with more maturity, I’m sorry it’s hard to describe. <br><br>My brother has a new girlfriend, she’s very nice, very mature, and a very intelligent woman, she’s 32 and she’s very much into class, she’s very classy, I suppose that’s why I’m here because I told her shit about the class.<br><br>My brother and his girlfriend have only been dating for a few weeks, so they just kept it on the down low, but she wanted to meet his daughter and my brother wanted his girlfriend to meet me and my husband, my brother and his daughter live with us temporarily but that’s a whole different story. <br><br>So last Saturday my husband and I are chilling in the living room, drinking wine, minding our own business when my brother asks if he could introduce his girlfriend, my husband and I are like sure, why not? He introduces herself, she’s very kind, very confident, I like her, she was a very nice girl. My brother ends the date and said he’ll call us later. <br><br>Next Saturday, my brother’s daughter is chilling with us, we’re all in the living room again when my brother and his girlfriend shows up, she’s holding a bottle of wine and she’s dressed in a dress and heels, she looked stunning, she was very classy. <br><br>They’re chilling for a bit, my brother asks if it’s okay if she meets his daughter, we’re like sure, what the hell, why not? I guess my brother could see the confusion in my husband’s and my face. So he introduces his daughter to his girlfriend, she was very nice.<br><br>Now I’m not sure what happened next, or what my brother did or didn’t tell his girlfriend, but she starts being very sexually suggestive towards my brother in front of my niece, like towards his butt, his abs, his face, his Smile, his lips, I’m sure my niece was very confused, shit, *I* was confused. <br><br>I know I’m the AH, I just can’t stand the thought, so I told my brother to take her outside, I told her she’s being inappropriate, she’s being a Bad influence on my niece, she looked like she was about to cry, I told my brother he needed to talk to her, he looked pissed.<br><br>Now they’ve both been ghosting me and my husband, I feel like I might’ve been an asshole, was I?<br><br>Edit: I just want to add that my niece didn’t say or do anything during the whole thing, it was very weird.