My best friend and I applied for the same job. She got shortlisted and I didn't. I hugged her, helped her prepare, and told her she deserved it. All of that was genuine, but another part of me secretly hoped she would fail the final interview.
She got the job. I went home after celebrating with her and cried out of jealousy. Years later, I still feel ashamed because she has supported me through everything. I learned that you can love someone and envy them at the same time, and knowing that about myself was uncomfortable.