What's the plural form of guestfriendship? Here's the word you're looking for.
Answer
The noun guestfriendship can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be guestfriendship.
However, in more specific contexts, the plural form can also be guestfriendships e.g. in reference to various types of guestfriendships
or a collection of guestfriendships.