Have/keep a foot in both camps
Definition 1 of 1
Pro Tip 1/3Neutrality
Use this phrase when someone doesn't take sides and is neutral in a dispute or disagreement. 
During the family argument, he kept a foot in both camps to avoid conflict.
Pro Tip 2/3Balancing Act
It suggests a delicate balance, implying skill in handling a sensitive situation without upsetting either side. 
The mediator had to keep a foot in both camps to negotiate effectively.
Pro Tip 3/3Indecision
Sometimes it can imply that a person is indecisive or unwilling to commit to a position. 
Although the topic was controversial, he chose to have a foot in both camps.