A mystery bug between my iDevices

Hi everyone,

I have a mysterious bug happening between my two 27 inch iMacs. When my friend is working on another iMac in Microsoft Word, and I am working on InDesign on another iMac, whenever my friend copy and paste, whatever he copied is pasted on my InDesign document that I am currently working. In some cases if he delete something from whatever document he’s working on, it deletes whatever I am working.

This whole thing is so annoying and it’s causing me a lots of inconvenience.

Anyone here experienced the same thing, your help will be very much appreciated.

Thanks

Veikko