Planar-supported phospholipid bilayers are responsive surfaces that reconstruct when macromolecules adsorb. This review outlines the phenomenon of lipid diffusion “slaved” to or significantly controlled by that of macromolecular adsorbates. To elucidate such systems, we discuss the value of spatially resolved experiments at the few-molecule level, lipid diffusion compared in outer and inner leaflets of the supported bilayer, and a simple method to minimize defects by the strategy of “electrostatic stitching.”