We have been together for 6 months. One day she suddenly started texting a guy that is a common friend every day. At first I didn't mind because we all have lives and friends and I also thought it is innocent. But this kept on going on for a week and it was everyday texting, memes and hearts. She was in a bad mood because of uni one day and didn't want to talk to me even though I wanted to help her and cheer her up. She stonewalled me and was very distant. Yet, I saw her sending a message to that guy asking how he is and how his day went. That hurt me very bad because she didn't want to talk to me at all but with him she was friendly and affectionate. For some reason I let that slide... Later, she apologized for treating me like that.

All was good until one day we were in my room and, in front of me, she texted him hearts and that she "will miss him" with emojis and that they can "suffer together through the quarantine". I asked what is going on and she said that he is just a friend and it is her way of texting people. I asked to see the messages. It was full of emojis, hearts and cheesy texts that to me are flirting. I told her that that is not acceptable to me and she told me that it is just how she texts all of her friends. She told me that I am insecure and that I don't trust her.

Again, I don't mind her texting anyone for business or to catch up with a friend. Also we see each other because we go to the same sports club in uni and is not like they haven't seen each other for a long time. Yet, she was texting this guy everyday in such a way and even in front of me while giving me the cold shoulder. I know how she texts her best male friends and girlfriends and she does not text them everyday at all! Even the ones she sees only when she goes home in her country.

This bothers me and I think I should interfere. What do you think I should do?