backdoor man
01
地下情人, 搞地下情的男人
a man who has an intimate relationship with a woman who is already in a committed relationship or marriage, often without the knowledge of the partner
disapproving
idiom
informal
例子
Isabella suspected that her partner was a backdoor man when she discovered secret messages on their phone from another woman.
他在镇上以地下情人闻名。
