"Sarah Dale" wrote in message
...
Ed B wrote:
Perhaps I'm just being a **** and the thing really should fit, but I
spent a good half hour last night trying to screw it on without cross
threading it. When screwed on as hard as possible it still squirts
everywhere, suggesting the plastic bit is too big for the tap I have.

You may have the wrong size connector (implied by it being difficult to
screw on), or possibly the rubber washer or O ring which normally provides
the watertight seal inside is missing. These things are cheaply made and low
precision however, and dripping connectors are not uncommon.