I am a few months into my PhD and my supervisor and co-supervisor are close friends.
Unfortunately, I find that my co-supervisor is not useful – he doesn’t provide any help or input into my project. Additionally, he has given me a hard time on more than one occasion, e.g. making a derogatory comment about the source of my PhD funding, not including me in discussions with his other PhD candidates (although I was physically present), and asking me to buy items for another PhD candidate using my budget.
I would like to stop being supervised by my co-supervisor, but I have not yet built a relationship with another academic that I could ask to take the role.
Do I need a co-supervisor? Can anyone recommend ways I deal with this situation?