Hi everyone! FTP, etc.

I (F18) recently started dating my boyfriend (M19) about 2 months ago. Before we were "official" we were talking for a few weeks, because I met him when we were both in high school. I also met one of my best friends (F18) when I was in 10th grade and she was in 9th (she is currently a senior in HS and I just started college).

My now-boyfriend started talking to me after I had got out of my last relationship, which I had been in all through high school. It had been a few months since the break up and I felt like I was finally ready to move on and find someone else, so when he asked me if I wanted to hang out and catch up I agreed.

We got along really well and had lots in common, and I quickly got feelings for him. He said he had had a crush on me since 11th grade, which I knew to be true because he had attempted to ask me out once my junior year and again my senior year (I had turned him down both times due to the fact I was still in a relationship already, but he wasn't pushy about and was respectful both times I turned him down).

Before we were official, all my friends knew I was seeing someone, at first didn't specify who because I figured most of them didn't know who he was. After I said his first name, my one friend asked if his last name was his last name and I confirmed it was. Then, my friend got upset and stopped talking to me when I asked what the problem was. I was genuinely concerned because she had a few interactions with him that I was vaguely aware of but I didn't know exactly what had happened between them.

When I finally got it out of her, she told me that while we were all still in HS, he was flirting with her after she had went through a breakup and it made her feel like he was trying to hook up with her and take advantage of her during a rough time. She also claims that he was flirting with both me and her at the same time, though I have no way of confirming nor denying that. She says this happened around the time he first asked me out (me and him would have been in 11th grade and her in 10th).

I was unsure of what to do and I told her that I really liked him and didn't want to stop talking to him, but I would if I was being a bad friend for seeing him. She told me that it was okay and that she wanted me to be happy, but her words &amp; actions say otherwise. I never talk about my boyfriend with her because every time I do she gets mad and I can tell she doesn't really like us being together. Occasionally, she'll say something along the lines of "How's your boyfriend?" and roll her eyes or something when I answer. I don't really understand the big deal, he was just flirting and it's not like they hooked up or dated, if he was actually her ex boyfriend or something, I probably wouldn't be with him, but this was years ago and I have confirmation that he apologized to her.

So, AITA for continuing to stay with him even though she isn't cool with it?