sit on the fence原来是指“在分家产的时候，骑在分割家产的篱笆上，不知应该选择哪一边”，现在这个短语常用来表示：“保持中立，采取骑墙观望的态度”。因此，当美国人说"In order not to offend either oft hem, I prefer to sit on the fence."时，他/她要表达的意思就是:"In order not to annoy either of them, I took a neutral stance on this issue."、"I'd remain neutral in the event so as not to displease either of them."。
Benjamin: Why not express your opinion? Which side are you on?
Terry: In order not to offend either of them, I prefer to sit on the fence.
①What do you think of their suggestions?
②I don't really know what happened.
③Both of them are reasonable, but also one-side.
④What's your opinion?
1. neutral adj. 中立的
Let's meet on neutral territory.
Those who had decided to remain neutral in the struggle now found themselves required to take sides.
Switzerland seems to be a permanently neutral state.
2. stance n. 立场
The Congress had agreed to reconsider its stance on the armed struggle.
They have maintained a consistently neutral stance.
His stance towards the story is quite similar to ours.