Am I wrong on this

TL;DR; : This is a sample summary of the TLDR rule, all things are bold. Is this going the right way?**.

So my partner works with this girl who I had no problem with at all. She started being over the top nice to me out of the blue. My partner suddenly started having to work past 5pm to 12/ 1am every night it seemed like. One day he was driving and he wanted me to message his mom back… a text came in from that girl. I didnt think anything of it but she was thanking him for door dashing her food. Mind you there are days when I can’t leave my desk at work and he throws a fit if I ask him to door dash me food. From there odd hour calls and text from this girl started coming through. 3 am, 5 am etc… and I hate to say but something just started to feel off. The girl was saying how she was with a man etc and the description matched my partner. I thought it was odd and was hmmm we just have the same taste. so I ask my partner if he had met her man and gave him the description of what she said he looked like/ acted like and he said no her man is (different race, not country etc for example) not anything like she describe. I hate jumping to conclusions so I tried to brush it off. I told him I was uncomfortable with how much she was calling him and he acted like he understood. I see this girl at his work Christmas party and I say hi and she looks me up in down with disgust and ignores me and walks off. I was so confused on this. She was just begging to be my friend… so the energy was different. I say hi to her again cause I thought she didn’t hear me… ignored again. I told my partner of this interaction and he didn’t say anything, or how that was rude. Flash forward to me and my partner were out and we bumped into her and her partner ... She acted like I didn’t exist and was being rude. So I gave her a look and my partner has screamed at me and said how dare I do that to her and how rude that was. She said something to him about me making the face he said. Why was he not upset at her behavior with me??? Only how I made a face? I know this probably sounds stup but I just need to know am I crazy? Is there another unbiased takeaway on this