Hot Jupiter Roche lobe overflow evolution tracks, as computed by T. Hallatt & S. Millholland (2026; black data) and our implementation in REBOUND (colored data points). Blue, orange, and green data points correspond to hot Jupiters containing 10, 20, and 30 M_⊕ cores, respectively, which end mass transfer at differing periods and masses (for our choice of initial planet entropy 8k_B/m_H, where k_B is Boltzmann’s constant and m_H the hydrogen mass; see T. Hallatt & S. Millholland 2026). Our hot Jupiter evolution tracks begin immediately before catastrophic mass loss to save computation time by avoiding the slow tidal decay phase (﹩\dot{a}\lt 0﹩). Top left: orbital semimajor axis evolution (mapped to orbital period on right axis). Top right: mass evolution. Bottom left: stellar rotation frequency evolution (relative to breakup; mapped to rotation period on right axis). Bottom right: stellar quadrupole moment evolution. Our REBOUND implementation accurately reproduces the mass, stellar spin, and orbital evolution of hot Jupiters undergoing “lossy” Roche lobe overflow.