go out with

go (out) with (someone)

To date someone. A: "I hear that Kevin is going out with Katie—is that true?" B: "Yeah, they're a couple now." I'm going with Brad, so you better stop flirting with him!
See also: go
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

go out with something

to go out of fashion at the same time as something else went out of fashion. That style of dress went out with the bustle. Your thinking went out with the horse and buggy.
See also: go, out
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs. © 2002 by The McGraw-Hill Companies, Inc.
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References in classic literature ?
The old count, who had always kept up an enormous hunting establishment but had now handed it all completely over to his son's care, being in very good spirits on this fifteenth of September, prepared to go out with the others.