They were once close friends; now they've gone their separate ways.
Tips
usage
Literally 'each rushing east and west' — east and west stand in for 'different directions'. Often used about graduation, divorce, family scattering, or any breakup of a former group. Carries a wistful tone.
mistakes
Taiwan often pronounces 奔 as bēn (gèbēndōngxī) rather than bèn. Both are accepted; mainland standard is bèn here.