on the fence, sitting
on a fence, are all terms for someone
who refuses to make a decision. Usually it describes someone
who will not take
a stand on two very defined and clearly opposing options/opinions. This can be both good and bad.
Clair was angry that Mandy occasionally
used drugs; Mandy thought drug use should be legal. Angela was neither for nor against it, and sat on the fence about
it, instead trying to calm her friends down.
The politician, when questioned on abortion, sat on the fence
giving a clear opinion; he was afraid of losing support from
or the left.