My (23M) girlfriend (22F) was kissed by someone I told her I was uncomfortable with. Is this cheating?

Honestly I’m not quite sure what to think or who to blame so I’m posting this here. Me and my girlfriend have been together for almost 5 months now.

A month ago my girlfriend and I got into a fight because I pointed out how a male coworker (29M) of hers was clearly showing signs of interest in her (taking hours off of work to help her with chores, buying her dinners, gifts, etc) and I told her I was uncomfortable with her spending alone time with him. She told me that I was overreacting and that she’s allowed to have friends. I told her that the second things got inappropriate between them, she would have to sever things with him to which she said she obviously would. The fight ended with both of us feeling really upset and we ended up taking space from each other for a few days, and things began good again after that.

Fast forward to now, my girlfriend suddenly tells me that during the few days we weren’t talking, her and the male friend watched a movie at her place and he kissed her during it. I asked if she tried to stop it and she said no, and that they didn’t do anything after that and they haven’t had contact since. I asked why she didn’t tell me and she said that she was afraid of losing me.

I guess I’m just lost on what to do now. It feels like she disrespected my boundaries for our relationship, yet I’m not even sure if this constitutes as cheating if she was only complicit with the kiss. Any advice on how to go about this situation would be greatly appreciated.

UPDATE

First of all, wow I did not expect nearly this many responses. I was hoping for at least 3 people to validate my concerns that this was cheating but instead I got a whole lot more and I appreciate the support everyone gave. I’ve read as many as I possibly could in whatever downtime I’ve had in order to process what’s happening to the best of my ability and I truly appreciate every single one. Second, I did end up breaking up with her. I blocked, and initiated no contact like the vast majority of you all suggested. It was terrible and I’ve been crying ever since, and still am even now but I haven’t doubted for even a second that this was the wrong choice. I definitely came to realize that this was not something I would ever be able to move forward from in time, especially so early on. This sounds cheesy but seeing so many people state what’s obvious to them yet is questionable to me is a huge wake up call for just how terrible my self-esteem issues are, and I cannot express enough how grateful I am for each and every response, no matter how harsh they may have seemed and I will try my best in the near future after this to work solely on myself. Thank you everyone❤️❤️