Apple polishing refers to the sexual act of rubbing the glans penis (dickhead) after orgasm/ejaculation. Outside of sex, to apple polish is to use flattery or do favours for someone in order to win their approval. The sex act definition is mostly in conflict with classic meaning, because many penises would disapprove of having their heads polished after ejaculation. Post-orgasm genitals are usually hypersensitive and a lot of people would find the act of apple-polishing quite torturous. However, it’s always worth noting that a lot of people enjoy being (consensually) tortured.