Hello!
My fiancée and I never really go out but when we do we always have family watch our children. We came to conclusion we should have a back up sitter as needed. We have a daughter who is 5 years old and a two year old daughter. They are super easy to watch and have a routine when it comes to evenings.

When watching them I just ask if you would change the two year old diaper when needed. Give snacks or drinks when needed. The two year old and five year old get along for the most part. Just putting them to sleep at 8 if we stay out past that time.