Try "A Spot of Bother" by Mark Haddon. While being a very amusing book, it covers many aspects of human relationships within a relatively small number of people, fearlessly tackling such controversial areas as cancer, depression, adultery, divorce, child-rearing, and homosexuality - yet still manages to entertain, and reach a happy conclusion.
How realistic is it ? Well read it and make up your own mind.
Or you could try his earlier book "The Curious Incident of the Dog in the Night-time", an exploration of the trials of a young boy with Aspergers Syndrome - the boy himself is the narrative voice and it is difficult at times to deny his Mr Spock-like logic, even though it runs counter to our social norms.