如果你 stick your oar into something, 意思就是没有得到别人的允许或者邀请就自以为是的发表意见，插手管闲事儿。

例句

I was managing the project well until the boss came along and stuck his oar in!

We're keeping the plans for the party a secret – otherwise everyone will try to stick their oar in and give their suggestions for it.

I can't stand our new neighbour – she's always sticking her oar into our business.

请注意

另一个短语 to stick your nose into something 也有相似的意思，表示多管闲事儿。

David is always sticking his nose in where it isn't wanted.