Contract with the billionaire(he needs a heir)

He needs a heir for him to acquire his grandfather’s property and he wants it without getting into any relationship or marriage after his terrible breakup with his ex girlfriend he vow not to marry. 
After trying everything when he doesn’t succeed in finding the suitable woman who is going to give him a heir, he personally sets out to find her and then he collides with her she was desperate for something which he promises to give, but keeping his condition of giving him a baby.
She does agree to the proposal but it surely does not end up the way they had planned out.
Will they end up getting married as times goes on or she will leave his heir and explore her personal life?