There's a shit ton of backstory here so bear with me.

I [19F] was best friends with a girl [18], we’ll call her “Ruth” for 7 years, from 6th grade to the end of my senior year. She has always had a small circle, but her both of her best friends (myself and my cousin) cut her off after having enought of her bs. Ruth has always had a lot of mental health challenges (manic depression, anxiety, possibly BPD...?) that she does a very poor job of managing. Because of this, Ruth got herself into a lot of fucked up situations, (toxic relationships, drug abuse, etc..) and I was ALWAYS there to pick up the pieces for her.

I would drop everything to help her whenever she needed and was treated like shit in return. I was, and still am, young as fuck, dealing with problems that were wayyy over my head. Ruth was unwilling to receive professional help and wouldn’t accept my advice either. Anytime I brought up concerns about our friendship, she told me that she wouldn’t change herself and that I was just “insecure”. She gaslighted me into believing that my problems were insignificant, and then when I was going through a debilitating period of anxiety and depression, she was absent from my life. She is manipulative, delusional and bad person and thru it all I always tried to be the best friend I could possibly be to her.

It has been about 9 months since I removed her from my life. I havent seen her since September 2019, and spoke to her only once, in March, to get some closure. Recently, I have been talking to her ex-boyfriend, “Tom” who was one of my best friends before he and Ruth broke up (they broke up summer 2018). I met Tom in 2017, months before he met Ruth, and since the beginning there has always been INSANE sexual tension between us. We have kinda hooked up on several occasions but could never fully go through with it for one reason or another. He is currently in school across the country but his fam still lives about an hour from me.

Our conversations have been extremely flirty and sexual and we both have talked a lot about how attracted to each other we are. AITA for wanting to fuck him the first chance I get?? I’ve never wanted someone so bad and I want nothing to do with Ruth. The only reason I even feel slightly guilty is because the end of my relationship with Ruth is pretty fresh. PLEASE HELP I WANT THIS BOY SO BAD BUT I DON’T WANT TO BE A HORRIBLE PERSON