If you want to have 0 flag then please use notranslate BBCode it will not be translated AT ALL - it means not to any language. Please consider is it what you really want - if you support also other languages (not only those 2) then much messages will be not translated at all.

This is example of notranslate BBCode usage: This will not be translated at all

Also translation for bilingual users shouldn’t be a problem - you have included original message.

If you wan for example messages in Catalan not translated on language X (but for others translated) then you will have to:
1. have those messages marked as Catalan
2. modify vBET code for BBCode handling by adding condition which will return original text for this translation pair.