“I'm pleased to meet you.” “The feeling 'is mutual'!” [=I'm also pleased to meet you]
They met through a 'mutual' friend. [=a person who was a friend of both of them]
Her fans love her, and the feeling 'is mutual'. [=and she loves her fans]
(..) He can't come. So what happens to me? Nothing. Go back to your life. If I could I wouldn't file for a divorce. Consent has to be mutual. He just gave his. Do you agree to a divorce? If she prefers to leave her family to go live abroad, yes I do. He agrees. (..)2011 A Separation