Roche lobe filling factor evolution of 60 + 45 M_⊙ systems at different orbital periods. Models accounting (not accounting) for tidal interactions are represented in solid (dashed) lines. Left panels: Hydro models: Right panels: Magnetic models. Upper panels: Primary star evolution. Lower panels: Secondary star evolution. For each simulated system a dot indicates whether the primary or the secondary fills its RL first (solid dot for the models with tides, empty dot for the models without tides).