Secular evolution over 3 Myr of the test system with non-null radii and a distant perturber. The assumed parameters are: M_s = 1 M_⊙, R_s = 1 R_⊙, M_pl = 0.06M_jup, R_pl = 0.4R_jup, and M_pert = 1M_jup. The initial values are: e = 0.15, a = 0.3 AU, i = 0°, and ψ = 0° for the main planet and e_pert = 0.01, a_pert = 5 AU, and i_pert = 75° for the perturber. Left: eccentricity (blue) and mutual inclination (red). Right: semi-major axis.