Because it is absolute and can hide important facts from easy discovery, the attorney-client privilege is hard to create, narrow, and fragile. Among other things, even friendly third parties' presence can abort privilege protection.
In Swyear v. Fare Foods Corp., Case No. 3:16-cv-01214-SMY-RJD, 2017 U.S. Dist. LEXIS 107939 (S.D. Ill. July 12, 2017), a Title VII plaintiff brought her mother to her initial lawyer consultation. The court bluntly held that "the presence of her mother during the consultation waived the attorney client privilege." Id. at *5. The court also rejected two arguments plaintiff advanced to avoid such a waiver, holding (1) that the mother was not a joint client, because "there is no evidence that [plaintiff's] mother sought legal services"; and (2) that "[plaintiff] and her mother did not share a common interest." Id.
Perhaps because plaintiff's lawyer did not raise it, the court did not address possible work product protection for plaintiff's communications with her new lawyer. Because the work product doctrine is not based on confidentiality and is much more robust than the privilege, friendly third parties' presence normally does not abort that separate protection.