100 Phrasal Verbs in 100 Days 26/100: To Cheat On Someone 👩❤️💋👨💔🙎♀️ Today's phrasal verb, to cheat on someone, means someone in a committed relationship is secretly romantic with another person. It is like breaking a promise to be faithful to your partner. Example: • "She discovered he was cheating on her when she saw messages from another person on his phone."