Contact mechanics and fluid flow in rough fractures are actively researched topics in reservoir engineering (e.g., enhanced geothermal systems, CO2 sequestration and oil- and gas-extraction) to estimate reservoir productivity or leak-off. Mechanical and fluid flow processes in reservoirs are often tightly coupled and exhibit a strongly non-linear behavior. Understanding hydro-mechanically coupled behavior in fractures is complicated further by highly variable fracture geometries [3, 4]. We present a simulation approach for hydro-mechanical processes in rough fracture geometries with variational parallel transfer operators. The contact problem at the boundary between the two rough fracture surfaces is solved using a finite element formulation of linear elasticity on an unstructured mesh. The contact formulation uses a mortar method with Lagrange multipliers and does not use a penalty parameter or other regularizations. For the Navier-Stokes formulation of the fluid we use a finite element formulation on a structured grid. Information between the meshes is transferred via the variational transfer operators, whereby the solid interacts with the fluid by enforcing velocity constraints at the solid-fluid interface and the fluid interacts with the solid by converting the fluid velocity into a pressure force acting on the solid.