  Massive stars in the red supergiant (RSG) phase are known to undergo strong
mass loss through winds and observations indicate that a substantial part of
this mass loss could be driven by localised and episodic outflows. Various
mechanisms have been considered to explain this type of mass loss in RSGs, but
these models often focus on single-star evolution. However, massive stars
commonly evolve in binary systems, potentially interacting with their
companions. Motivated by observations of the highly asymmetric circumstellar
ejecta around the RSG VY~CMa, we investigate a scenario where a companion on an
eccentric orbit grazes the surface of a red supergiant at periastron. The
companion ejects part of the outer RSG envelope, which radiatively cools,
reaching the proper conditions for dust condensation and eventually giving rise
to dust-driven winds. Using simple treatments for radiative cooling and
dust-driven winds, we perform 3D smoothed particle hydrodynamics simulations of
this scenario with a $20\,M_\odot$ RSG and a $2\,M_\odot$ companion. We follow
the evolution of the binary throughout a total of 14 orbits and observe that
the orbit tightens after each interaction, in turn enhancing the mass loss of
subsequent interactions. We show that one such grazing interaction yields
outflows of $3\times10^{-4}\,M_\odot$, which later results in wide asymmetric
dusty ejecta, carrying a total mass of $0.185\,M_\odot$ by the end of
simulations. We discuss the implications for the evolution of the binary,
potential observational signatures, as well as future improvements of the model
required to provide sensible predictions for the evolution of massive binaries.
