I assume you have two fields on the label for names, and a fixed "and".
If you combine the fields first, into "John and Jane" (in a single field), you can control the "and" part in the calculation of that field:
Field calc could be something like:
If ( FName2 = "" ; FName1 & LName ; FName1 & " and " & FName2 & " " & LName )
Another way is a calculation field with a calc like:
Substitute ( List ( husband ; wife ) ; ¶ ; " and " )
With the exception of a missing space holder between FName1 and LName, this worked perfectly. I chose to not store calculations and all seems to be well. Jack sends.