Suppose we have two objects where the distance over time decreases. Now, as I understand it, general relativity says that we can observe the Universe from the perspective of both objects an get a equal valid view, i.e. it's squally valid to say that object $A$ is in rest while object $B$ is the one moving as to say that $B$ is at rest and $A$ is moving.
Now, GR also tells us that the relativistic mass increases by the gamma factor $\gamma = \frac{1}{\sqrt{1-(\frac{v}{c})^2}}$. As the mass increases, so must the gravitational force and thus the curvature of spacetime.
But, now GR states that the curvature of spacetime is not relative, but absolute ($G_{\mu v} = R_{\mu v} -1 \frac{1}{2} g_{\mu v} R$). How is this consistent with claiming that both $A$ and $B$:s perspectives are equally valid?