Maybe I am injecting little to much of myself into this scenario, but I would be more than little disgusted if a guy confessed to me "hey, I thought of rufying/enslaving you."
Like, I understand that he had a change of heart and how current Garth is a good boy and a father but... yuck. It would make me feel sick.
Gweyr is a more forgiving person than I.
Seriously, most of men in CoC2 can barely pass a bare minimum for a husband.
Edit: I am being little to harsh on Garth since rape/infidelity/absent fathers are common place in this game. I just expected more from him, that's all.