You and Your Sister

"You and Your Sister" is a song by the American singer-songwriter Chris Bell, that appears on his only solo album I Am the Cosmos. It was released as a B-side to Bell's only single "I Am the Cosmos." The song is very similar in composition, vocals, and guitar playing to Big Star's "Thirteen," which Bell co-wrote with band mate Alex Chilton, as it is also an acoustic love ballad. It features backing vocals by Chilton.

Mark Deming of Allmusic described it as a "sweet, guileless love song" that "represents the sincerity and emotional innocence that Bell brought to his brief tenure in the band Big Star" that "make[s] more emotional sense than literal sense" and as "one of the great unknown love songs in the pop canon, a luminous and fragile ballad almost otherworldly in its beauty."

Two alternate versions of the song appear on the 1992 I Am the Cosmos release, an "acoustic version" and a "country version." It was covered by This Mortal Coil on the 1991 album Blood, along with "I Am the Cosmos", by Seana Carmody on the 2007 album Barn Songs and by Mike Daly on A Tribute to Big Star. It was also included in the 2009 Big Star box-set release Keep an Eye on the Sky.