By taking a Molecular Orbital (MO) perspective we can understand to expect an increased in situ electronegativity for elements that partake in hydrogen bonding. In MO theory, a hydrogen bond is primarily an orbital stabilization effect, i.e., an interaction driven by the lowering of electronic energies. In brief, the MO responsible for such an interaction is typically delocalized over all participating atoms (a two-electron-three-center bond over O, N and H in our example). The in situ electronegativity that we quantify is effectively a spatially resolved average MO stabilization (c.f., Eq.3). As such, our methodological framework allows for a natural conceptual merger between MO theory and quantum chemical topological approaches to electronic structure analysis.