tit for tat
noun [ U ] disapproving uk/ˌtɪt fə ˈtæt/ us/ˌtɪt fɚ ˈtæt/
以牙还牙,针锋相对
actions done intentionally to punish other people because they have done something unpleasant to you
I noticed she didn't send me a card - I think it was tit for tat because I forgot her birthday last year. 我发现她没有给我寄贺卡——我觉得她这是报复,因为去年我忘了她的生日。