I have 2 boxes A and B. A is heavier than B. Will the kinetic friction coefficient of A sliding on B and the kinetic friction coefficient of B sliding on A be different?

I think they won't because they have to have the same amount of kinetic friction since it is an action-reaction pair. Therefore, since A and B have different masses, the kinetic friction coefficient would be different for the equation F = u(k) * N or kinetic friction = kinetic friction coefficient * Normal force