I need an example of a finite, non-abelian group $(G, \cdot)$ which satisfies the following condition:
If $d$ is a metric on $G$ such that $d(ax, ay)=d(x,y), \ \ \ \ \forall a,x,y \in G$,
then $d(xa, ya)=d(x,y), \ \ \ \ \forall a,x,y \in G$.
Could you help me find it or maybe tell me where to look for it?
Thank you.