all dressed up and nowhere to go

All dressed up and nowhere to go (or all dressed up with nowhere to go) is a way of saying that you are fully prepared and ready for something that isnt going to happen. This can be used in the literal sense where you dressed up for a special occasion but now the plans have changed and you literally have nowhere to go, or it can be used for other situations where you are prepared but it is moot because the thing youre ready for is no longer valid.