AITAH: My girlfriend went out to the bar then days later wanted to become "friends"
My girlfriend and I have been together a month. We have done stuff like go out to restaurants, events, so on. Recently she was talking about her new friends at a bar she frequents while I am out working (I work the night shift). She was saying how she got along with them and was explaining how she met a person like her with some of her issues and I didnt think to much about it.
A couple days later I receive a message about her being at the bar with her "new friends" and I joke about being jealous of her new friends. She got upset at me saying I cant be mad about her new friends. Recently I went over after work and she went to tell me she wanted to be "friends" not girlfriend/boyfriend and I was upset and asked what I did wrong. She said it was nothing and I was wonderful, she just fell out of love with me. I asked some questions and then I asked if it was because of a dude or something and then she brought up that she had "a crush" on the dude from the bar and claimed "it only lasted a minute or two". I dont want to assume she is flirting with this guy but I am worried because I feel like we were just leaving the honeymoon phase and she got bored of me.
Am I the asshole for feeling upset about this?
EDIT: For more context. We didnt break up, she brought up the idea of us being friends with benefits but backed off near the end of our talk because she didnt "want to lose me and be alone".
EDIT AGAIN: So I went and told her how I felt and we broke up. Her in a relationship wasnt the person I knew through friendship and it was an entirely different story. Sadly our family's are close and we have known each other for a while but I didnt want to continue something that felt doomed. Thank you for all your assistance. Apologies for the lack of information regarding this, I know she watches YouTubers and occasionally visits this subreddit so I wanted to be slightly vague on the offchance she read this soon after I posted this.