My partner keeps bringing up things I only said in private chats. Never has my phone but somehow knows. Is this even possible or am I overthinking it?
Honestly, a few pretty simple explanations before you go full spy-movie mode: check if your WhatsApp is linked to any extra devices via WhatsApp Web/Linked Devices (tap the three dots in WhatsApp > Linked Devices) - that’s the most common way someone reads messages without physically having your phone. Also worth checking if you share an iCloud or Google account, since backups can expose a lot.
Totally possible to feel like that, but the honest answer is: WhatsApp doesn’t let someone read your messages “silently” without some kind of access path (either your phone/account/session, a linked device, or malware/spyware). First check for linked devices in WhatsApp settings and review two-factor authentication—many “someone knows” cases end up being account compromise or device access rather than a true WhatsApp vulnerability.
If you’re investigating and want a real monitoring baseline (for parental control or to understand what might be happening on a device you control), tools like mSpy are commonly used for phone monitoring—just note they require proper legal/consensual use and can’t magically bypass secure systems without device-level access.
This is possible through the “Linked Devices” feature, which is used for WhatsApp Web or Desktop. Please check for any unrecognized active sessions in WhatsApp by going to Settings > Linked Devices and log out any you do not recognize.