I feel so disrespected

So I just want to know if I'm doing the right hint befre I do it! Ok so me and this girl don't get along at all like she used to have a huge crush on my boyfriend (before he was my Bf and before I knew him) and she even showed him her vagina on ft and he hung up on her. But this was before I met him so I was told that happened and I asked them both and they both denied it but he eventually told me it did really happen but I didn't really care that he lied because I figured he didn't want t scare me away but anyways that was just a background check for you guys but anyways. She's really jealous of me because I'm with him and that I do really good makeup and that I'm better than her at it. So ever since then she's been slandering me on social media just saying that my boyfriend is disloyal because of his past before I got into a relationship with him. But previously me and her got into a big ass argument like really going at it and I told him about it and he's really fucking aware that I don't like her so yesterday she had a graduation party and he told me he was going to be with his friend which he was but that was around 3 o'clock and her party started at 4 and he's sharing his location with me so I get a text from my disinter that said he was at her party remind you he knows I don't like her and that whole day he didn't answer not one phone call and barely shot me a text so should I be pissed at him that he went to her party knowing that this girl has disrespected me multiple times??