zijns weegs gaan - Wiktionary, the free dictionary

Literally, “to go his way”, with a fossilized genitive.

zijns weegs gaan

1. (idiomatic, intransitive) to go one's way

   Na de borrel ging ieder zijns weegs. ― After the drinks each went his way.

• May vary with different pronominal forms such as huns weegs, onzes weegs, and so forth, but zijns weegs is the most frequent followed by the feminine haars weegs.