relationships

i know there are boundaries in relationship, but isn't weird if your partner doesnt want to tell you something like so little? Like literally something that doesn't have much importance to it? For example, we were talking about where to work and stuff. And i suggested a place but they said that they didn't want to work there because they didn't like somebody there. And i was asking who, but they didn't want to tell me. I dont know I just thought it was weird cuz i mean we tell each other everything, and they said that the person doesn't even matter, so why is it so hard to tell me? idk now it seems like theyre hiding something about that person.