  We discuss the dRGT massive gravity interacting with spin-0, spin-1/2, or
spin-1 matter. The effective theory of a massive spin-2 particle coupled to
matter particles is constructed directly at the amplitude level. In this
setting we calculate the gravitational Compton scattering amplitudes and study
their UV properties. While the Compton amplitudes generically grow with energy
as $\mathcal{O}(E^6)$, we identify regions of the parameter space where they
are softened to $\mathcal{O}(E^4)$ or even $\mathcal{O}(E^3)$, which allows for
a larger validity range of the effective theory. In these regions, both
positivity and beyond-positivity of the forward Compton amplitudes are
fulfilled, and the equivalence principle automatically emerges.
