it takes two to tango

Probably based on earlier sayings of the it takes two to‥form (see above). Sung by Pearl Bailey, the Hoffman and Manning song (quot. 1952) was a worldwide hit, giving this saying instant international currency.

There are lots of things you can do alone! But, takes two to tango.
[1952 Hoffman & Manning Takes Two to Tango (song-title) 2]

As for negotiation‥the President has a firm, and melancholy, conviction: it takes two to tango.
[1965 Listener 24 June 923]

Remember. It only takes two to tango, and neither of them has to be you.
[1991 Times 22 May 14]

Deep down, I know it takes two to tango and the blame should lie with them equally.
[1999 Bella 25 May 16/2]

Related to: co-operation

Bibliography of major proverb collections and works cited from modern editions is available here.

The active cooperation of both parties is needed for some enterprises, as in We'll never pass this bill unless both parties work out a compromise--it takes two to tango. This expression dates from the 1920s, when the Latin American tango became a very popular dance. It was popularized by the singer Pearl Bailey in her 1952 hit song of that name written by Al Hoffman and Dick Manning.