have a finger in every pie从表面上看是“在每个馅饼有一个手指”，对应的就是中文“凡事插手，到处干预，爱管闲事”。

【例句】
He is such a person who has his fingers in a lot of pies, many people can't get along with him.
他是一个爱管闲事的人，很多人和他处不来。

He very much likes to have a finger in every pie.
他很喜欢什么事都插上一杠。