Anyone any bright ideas on the following tale of grief!.

Been installing a replacement kitchen in my parents old house and
before the Christmas "shutdown" had very carefully spent some time
preparing two worktops with a very carefully cut "masons mitre", all
very neat etc.

Went back there today, and the pipe that takes the drainage from the
condensing boiler had come apart slightly so that some water had
trickled down and instead of running away harmlessly across to the front
of the worktop, had yes you've guessed!, made its way into the as yet
untightned joint which of course has now swollen up and has a mismatch
in size!.

Anyone any bright ideas on how to sort this without replacing both bits
and cutting them including all the other openings etc?....

TIA....
--
Tony Sayer