Mr. and Mrs. Used to Be was released on Decca Records in 1965. This was the first duet album the pair would record together, and they would go on to record two additional studio albums together during the decade. The lead single, the title track was the biggest hit the duo would achieve, peaking in the Top 15 in 1965. Their second single from the album, "Our Hearts Are Holding Hands" was a Top 30 Country hit. The album consists of 12 duet tracks, some of which are cover versions of previous duet Country hits, including "A Dear John Letter" and "Are You Mine".
The album reached #13 on the Billboard Top Country Albums chart in 1965.