Wanna ask lang kung valid ba na maging uncomfortable ako when my jowa is with her kafubu dati?

Hello po, its my first time pumasok sa relationship NGSB po here. In my twenties male and my "jowa" also in her twenties. Now I have this problem she was in a friends with benefits situation before, and still shes friend with the guy and they go out together sometime (my times na may kasamang ibang friends may times din na silang dalawa lang). Now I allow them both to go out kasi friends sila eh, but meron me ibang feeling that nagseselos me or like di me comfortable when shes with that guy. She told me na din na nagusap sila if gusto pa ba nila maging friends with benefits but both said no. Does the feeling of being uncomfortable valid sa situation na yon? Need advice guy and what action should I do? Thnaks