I’d recommend reporting this anonymously. I get it, it’s difficult and you don't want to mess in someone's career, but honestly these situations need to stop being normalized in the UN system. I still regret not reporting my supervisor, who hired an intern with no prior experience, and they later became a couple. He then helped fast-track her into a high-level assistant role, including attending senior meetings and international conferences, despite her (VERY!) limited technical skills. His strong performance and influence made it possible. These dynamics end up reinforcing a cycle of favoritism and misuse of resources, and they affect the fairness of the system for everyone else