¹²CO gas radii as a function of the projected separation. Blue squares and red circles show the observed ratio in the circumsecondary discs and the circumprimary discs, respectively. Blue plus symbols and red crosses show the expected ratio from the tidal truncation model in the case of circular orbits (e = 0) for circumsecondary discs and circumprimary discs, respectively. The longer the dashed line that links observed radii with models, the weaker the agreement with the zero-eccentricity model.