Hello all
I am writing to ask for advice as to what to do with a situation that has been affecting me negatively on a psychological level. I have a PhD colleague who lives with me and who likes to always tell me about how she has a special bond with my supervisors. Indeed, she is friends with one of them. She asked me a number of times about their performance as supervisors, and I always tried to divert the discussion to a different topic as I don't like gossiping about my supervisors with others. However, a few times she mentioned to me that she had discussed my matters with them, some of which I considered a bit personal and I wouldn't like other people to interfere with, which made me feel really uncomfortable.
The fact that in front of me she discusses other colleagues/seniors/students in a very derogatory manner and then acts so nicely with them is making me feel even more insecure about the nature of discussions she had with my supervisors about me.
I wanted to email my supervisory team and ask to kindly not discuss me with other colleagues, but I hesitated as one of them as I said is a friend of hers. Has anyone experienced a similar thing and how did you deal with it?
Thanks in advance.

This is such a tricky situation. I'd be tempted to just raise it with the colleague in your house - say that you'd prefer if she didn't raise things - in a casual kind of way but obviously meaning it. Cos if we assume that she is the one raising things and not the supervisors, then it may stop. Also, I'd kind of distance myself somewhat from her - just be formal housemates and not friends. Perhaps doing this could solve the problem rather than directly involving the supervisors - when it may not actually be their fault / them who are raising it. It sounds as though your housemate is the gossipy one. But if you aren't really interacting with her anymore then she won't really have much fuel / interest in gossiping about you with your supervisors.

Others may have better advice. I haven't been in this exact situation but I do know when people cross boundaries it is sometimes best to gently but firmly let them know, or simply back off from them so they can't do it any longer.

What are they discussing about you? I am trying to understand are they talking about your project, your personal life or you as person? As people will talk about you behind your back regardless of what you do and you can't stop them. You can only ask them to not share certain details with other people or not tell them certain details in the first place. I would suggest being honest with your friend and that you think she shouldn't have said certain things to your supervisor. Say that you wanted to tell your supervisor yourself and you don't want her to interfere with it, no matter how good her intentions. As it sounds like you are more upset with your friend than your supervisor.

I have had some very gossipy friends and I have learnt the hard way you can only trust them with certain things. You don't have to stop being friends, just learn not to trust them with certain secrets.

I had some similar situation when I had a friend who used to talk with supervisor about other colleagues including me. The only solution I see is to do what Tudor_Queen suggested. It is not about the supervisors and you cannot tell them what to do. Also you cannot tell people who like gossip not to gossip. Just distance yourself from her. Do not be her friend and if possible not her housemate. If she starts to talk with you about supervisor and/or other colleagues, say I am not interested in the subject. If you see them talking about your project/personal/whatsoever leave them immediately. I am sorry to tell you that your housemate is poisoning the environment intentionally or unintentionally. You should go away from her as fast as you can.

She is a toxic person.
I would be moving out ASAP given the tie with your supervisors.
You certainly do NOT want to talk to your supervisors about this. That would be disastrous. Your flatmate could be bullshitting.
In the meantime, I would keep things civil with her but would cut her off socially with immediate effect.