Yes, text messages can be shared between iPhones using iMessage in iCloud for syncing all messages (iMessage, SMS/MMS) or Text Message Forwarding for SMS/MMS messages, both requiring the same Apple ID on the devices and proper setup in Settings, ensuring seamless updates across iPhones.
It can get confusing, because sharing an Apple ID with another family member allows them to see your text messages. This is because iMessage is designed to work across all of your Apple devices, like your iPhone, Mac and iPad.
iCloud exploitation
Your iCloud account is a gateway to all your synced data, including text messages. Someone can spy on your messages by: Logging into your iCloud account from another device to view message backups.
Your wife could see your text messages in a few ways. If your iCloud syncs automatically, or you have backups enabled, your messages might display on other devices that she can access. She might have installed monitoring apps on your phone, or simply be using a shared phone.
Note: Deleting and recovering messages only affects your iPhone and other Apple devices where you're signed in to the same Apple Account. You can't recover messages, attachments, and conversations for anyone else.
On your iPhone or iPad, go to the Settings app > Apps > Messages > Shared with You, then turn off Automatic Sharing or turn off Shared with You for a specific app.
Android phones can hold onto old Wi-Fi Direct pairings. When two devices come into close proximity, they may automatically reactivate previously established file-sharing links. This can make it seem like the phones are communicating with each other even when nothing unusual is happening.
Phone mirroring broadcasts what you see on your screen to another device. If done without your consent, it can reveal sensitive information — your private messages, passwords, and other personal data — to someone else.
Phone cloning happens when a hacker duplicates your phone's unique identifiers, such as the IMEI or SIM card data, to create a replica. This means someone can clone your phone without you knowing and gain access to your calls, messages, login details, and cloud backups.
Modern phones keep lengthy records of our messaging history, making it easier for a prying spouse to read all your conversations once they have access to your phone data. They can obtain this using a number of methods, such as through shared cloud accounts, or by using spyware.
Remove your associated iPhone or iPad
Q: Why Are My Two iPhones Linked? A: Your two iPhones may be linked together to synchronise iTunes and iCloud data while allowing all purchased apps to be visible on both devices. This may be essential for someone with two phones for different uses but wants to retain personal information on both.
Obtaining a spouse's text messages can ordinarily be done in two ways. One way might be to send a letter to the cell phone carrier, through an attorney, explaining the need to preserve text messages for a divorce case.
The answer has not changed. Permanently-deleted messages are deleted permanently. Find a copy (such as a screen recording of scrolling through the messages) created prior to deletion. Ask a participant in the conversation for their copy.