Answer: uninvited

AnswerCrossword Clue
UNINVITEDDescriptive of a "gate crasher."
UNINVITEDLike party crashers
uninvitednot invited
uninvited(of a thought or act) Involuntary, unwelcome, or unwarranted
uninvited(of a person) Attending somewhere or doing something without having been asked