two's company

two's company(, three's a crowd)

A third person would make a group of people awkward or uncomfortable, especially when the other two are lovers or close friends. I was worried when the new boy moved into the neighborhood and started hanging out with John and his best friend—two's company, but three's a crowd.

two's company

used to indicate that two people, especially lovers, should be left alone together.

The expression is a curtailed version of the proverb ‘Two's company, three's a crowd’ (or, in an alternative formulation, ‘Two's company, three's none’).

See also: company

two’s ˈcompany (, three’s a ˈcrowd)

(saying) two people, especially two lovers, are happier alone than within a group of three: ‘Do you want to come with us?’ ‘I don’t think so. Two’s company...’

See also: company