I am close to the end of my second of five years of funded PhD in philosophy. Because of personal interest, I would like to start a part-time BA in Law on the side, which is tailored to people who have a job, thus it only has non-mandatory evening classes. I want to talk about this with my supervisor because I don't want to hide this from him, but at the same time I fear he might think that I don't take the PhD seriously or that I am a fool for trying to do to much.
Long story short, I would like to be honest without giving him the impression that I don't know what I am doing with myself. Any suggestions on how to approach this? Any similar experiences?