irreconcilable differences
idiom
formal
: inability to agree on most things or on important things
They are filing for divorce, citing irreconcilable differences.
Legal Definition
irreconcilable differences
noun plural but singular or plural in construction
ir·rec·on·cil·able dif·fer·enc·es
ir-ˌre-kən-ˈsī-lə-bəl-
: substantial incompatibility between marriage partners that is a broad ground for especially no-fault divorce compare irretrievable breakdown of the marriage