Self-centered and Thick as thieves

Self-centered adjective - Overly concerned with one's own desires, needs, or interests.

Thick as thieves and self-centered are semantically related. In some cases you can use "Thick as thieves" instead an adjective phrase "Self-centered".

Self-centered and thick as thieves are semantically related. Sometimes you can use "Self-centered" instead an adjective phrase "Thick as thieves".