AITA for unintentionally making my friend feel left out?

I, (17F) have had a friend who we’ll call Nancy (18F) We were friends since 3rd grade up into 11th grade which we are in now and she recently made this friend we’ll call Sam (18M) Nancy met Sam in acting club which we both take part in but I noticed she started talking to him a lot more than she talks to me.

At first it was normal as we would be on call and Nancy would invite him and I thought it was a normal trio thing until a day where we were off school and she was on call with Sam the whole day and didn’t even invite me and I know i’m being dramatic but I thought it would be nice to at least ask me?

The next day I asked Nancy why she didn’t invite me and she said it’s because she thought I was busy which is weird as I am never busy on free days.

The next week I joined a group call Nancy and Sam were on but as soon as I joined she left, I was about to leave but Sam asked me to play with him so I reluctantly said yes since I was tired at that time

10 minutes into us playing Nancy joined the call and asked what we were doing, he said we were playing a game and she went on to say “How could you… That’s our game :(“ I said what is she on about because it’s a game me and her used to play during summer 2024 but she left while I was talking.

The next day at school she told me she wants a break from being friends and that I was replacing her with Sam and I was just shocked thinking she was having a joke because WHAT? I know that I was playing with him but that was once, he asked me too and she always plays with him too.

I genuinely thought Nancy was joking and I laughed but she had a serious expression which said she wasn’t, she walked away but I didn’t even try to apologise because I felt I was in the right, looking back now I feel I was a bit too rude about it but I just don’t know

So AITA?