See Jennifer Aniston Without Makeup
"Best #friends #no makeup #girl-time" McMillan, who's known the star for 20 years, captioned the pic.
The stylist recently joined the team at Aniston's Living Proof hair care line and is the man who gave the former Friends star her iconic "Rachel" haircut back in 1995.
"I know that was Jen's least favorite hairstyle because I hear about it every time I style her hair," McMillan told Marie Claire in June.
Aniston, who's engaged to Justin Theroux, has already asked McMillan to style her hair for her wedding, and says she won't do an updo.
"I like loose and natural hair because it goes against the formality of the dress," she says. "Loose, like 'I just got out of bed, maybe had a romp' hair."