A phony shows his true colors
genuine or phony
it doesn’t matter whether he is genuine or phony
a genuine person remains in your life
a phony disappears eventually
there is such natural law in human society at all times
a phony shows his true colors sooner or later
therefore, you don’t have to do anything special in front of a meretricious person
do what you need to do without hesitation
nobody disturbs you anything
all you need is perseverance to do what you need to do