Quick question. My dh's best friend is organising a surprise treat for my dh's 40th. I am helping him with arrangements and obviously we need to chat online/text/email. But his and my apple devices are linked via iTunes/icloud. If I use what's app, will it go onto his phone? I really don't want to ruin the surprise and have been mainly phoning him, but need to text as at work today.
WhatsApp, when I attempted to try it on my tablet, needed a mobile number (at which point I uninstalled it), so no, seems pretty likely you will be able to message between yourselves without it being obvious to your DH.
Text (as in SMS) is another matter, since that could easily be stored (I'm guessing there's an Apple App for that - I use one on my Android to log messages and calls). I'm guessing you mean WhatsApp messages, not text messages.
Incidentally, if you sent a friend a message via WhatsApp but their phone was off, would it be stored for them, to see later on when they went online again?