Wiktionary
vb. (present participle of sit on the fence English)
Wikipedia
"Sitting on the fence" is a common idiom used in English to describe one's neutrality or hesitance to choose between two sides in an argument or a competition, or inability to decide due to lack of courage. This is done either in order to remain on good terms with both sides, or due to apathy to the situation and not wanting to choose a position with which one doesn't actually agree. In simple form, it means to be usually quiet
Usage examples of "sitting on the fence".
I heard my name, and turned my head in surprise, and there he was, with his hat on and carrying his applewood stick, peer- ing up at me where I was still sitting on the fence.
He was standing under the tree when he saw the two Roogs sitting on the fence, watching him.
We'll have to start selling some of our own shares to get things moving, otherwise everybody's going to keep sitting on the fence.
We need to know who our friends are, who our enemies are, and how those sitting on the fence will jump if things begin to happen.