I am just looking up the full definition of tromboning, but here's another example:
Britney's chuff euph.
A situation whereby a much-anticipated reality in no way matches up to what you'd imagined it would be like, to the point that you begin to wish you'd never seen it. 'I got the Sky Sports so I could watch the Ashes series. A right Britney's chuff that turned out to be.'