unsociable (adj)

He was feeling unsociable so he stayed at home.
His unsociable behavior at social gatherings led to a reputation for being aloof and distant.
Some people may appear unsociable due to shyness or social anxiety rather than intentional aloofness.
Choosing a solitary lifestyle doesn't necessarily mean being unsociable; it can be a personal preference.
Encouraging team-building activities can help bridge the gap for those who tend to be more unsociable in group settings.