Y'all my fiancé is going out of town on the 21st for work and i don't know how to tell him without sounding rude that he…

Y'all my fiancé is going out of town on the 21st for work and i don't know how to tell him without sounding rude that he can't leave his child with me because he is disrespectful and doesn't listen at all. Mind you the child mother isn't really in his life he will see her for 2 days then won't see her at all for months.