Messages to this chat and calls are now secured with end-to-end encryption. Tap for more info.
When is this message prompted by WhatsApp? Just before the first message is sent by any of the two talker (this option is for sure)? When the contact is saved and the app detects that WhatsApp is installed in the other phone? When WhatsApp is installed in THIS phone and WhatsApp detects it is installed in the others phones? When WhatsApp is reinstalled and it detects it is installed in the others phones? Some of these? The whole of these?