Synchronized Morning Routine

A scene where two characters are washing up in tandem, and which includes them brushing their teeth and gargling while facing the mirror. Is generally presented as a cute scene, and the participants can range from relatives, Heterosexual Life Partners, those potentially in a romantic relationship, to romantic partners. Usually played as humorous.

Sub-trope of Morning Routine.

Anime and Manga

 * One episode of The Melancholy of Haruhi Suzumiya begins with Kyon and his sister doing this.
 * In Ichigo Mashimaro, a flashback shows 6-year-old Miu popping over to the Ito house to leave her wet undies and bedsheets and comes in on 10-year-old Nobue and her 6-or-7-year-old sister Chika brushing their teeth. It is cute, but that's not surprising.
 * This is part of the Training Montage in which Shinji and Asuka learn how to move in synch for a Monster of the Week in Neon Genesis Evangelion.
 * All three Paper Sisters do this in Read or Die. They think its cute, Nenene thinks its just creepy.
 * One of the openings for One Piece had the entire crew doing brushing their teeth together on a hillside.

Film

 * Torrance Shipman and Cliff Pantone in the movie Bring It On.
 * Doug and Steve in A Night At the Roxbury.

Live Action TV

 * Seen in Frasier.
 * Lorelai and Rory in Gilmore Girls have their routine.
 * Morecame and Wise's breakfast routine, set to the tune "The Stripper".

Webcomics

 * Kelly and Julian did this in a recent The Wotch.

Western Animation

 * Wallace and Gromit have a rather elaborate approach to this.