If someone cheats on their husband, wife, or partner, they have a sexual relationship with another person.
He's cheating on his wife.
他對妻子不忠。
I'd found Philippe was cheating on me and I was angry and hurt.
發覺菲利普對我不忠後，我又氣憤又傷心。
She has been cheating on her husband for years.
多年來她對丈夫壹直不忠實。
Don't go to that shop- they often cheat their customers.
別去那家商店，他們常常欺騙顧客。
He cheats at cards.
他玩牌時作弊。
You're not allowed to look at the answers- that's cheating?.
妳們不許看答案，那是作弊。
cheat的其他短語：
feel cheated ：上當受騙
Many people feel cheated by the government's refusal to hold a referendum.
由於政府拒絕舉行公民投票表決，許多人都覺得上當受騙。
cheat death （通常用於新聞報道）：to survive in a situation where you could have died死裏逃生，幸免於難
He cheated death when he was rescued from the roof of his blazing cottage.
他被人從他那熊熊燃燒的棚屋頂上救了下來，撿了條命。