My sister and I were playing a romantic duo.
Duo mean
pair, two, brace, duo, twosome
The noun 'duo' is a singular noun, a word for one group of two people or things (a pair).The plural noun is 'duos' a word for two or more groups of two people or things.
A pair or a duo
PC World's Digital Duo - 2005 is rated/received certificates of: USA:TV-G
Hao duo da mi - 2005 is rated/received certificates of: Argentina:13
The cast of Ren yu duo duo - 2005 includes: Chi Chung Lam as Plumber Vivian Hsu as Do Do Pinky Juan as Big Cat Duncan Lai as Smiley Dentist Andy Lau as Narrator Nana Tang as Sad Witch
Duo Valentianos - 1987 is rated/received certificates of: West Germany:12 (f)
Duo biao - 2008 is rated/received certificates of: Hong Kong:IIB Singapore:PG USA:PG (certificate #46632)
Duo ming jin jian - 1971 is rated/received certificates of: Germany:BPjM Restricted
Shen tou miao tan shou duo duo - 1979 is rated/received certificates of: Norway:15 (video premiere)
Qun long duo bao - 1988 is rated/received certificates of: South Korea:15
Jue qiao zhi duo xing - 1990 is rated/received certificates of: Hong Kong:IIB
Lao dou wu pa duo - 1991 is rated/received certificates of: Hong Kong:II
Gou hun zhen duo ming quan - 1978 is rated/received certificates of: UK:15
Madlax - 2004 Double Separation 'Duo' 1-18 is rated/received certificates of: USA:TV-14