That is a Scottish salutation wishing long life and prosperity.
(Literally, long may your chimney smoke.)
Will and Bailey will be learning that lingo come next fall!
And maybe he'll be whispering that in her ear.
(That was in good taste.)
You see, they've both been accepted to do graduate work at the University of Glasgow in Scotland!!!
Here's a picture of part of the university...
'Course I'll have to go see for myself just how different.