How to tell if he's cheating on Facebook?

Lately, my boyfriend has been acting a bit distant and spends a lot of time on his phone, especially on Facebook. He quickly hides his screen when I walk by, and I noticed he changed his password. Are there any signs or red flags I should look out for on Facebook that might indicate he’s cheating? Any advice would be appreciated.

Hey, I totally get how unsettling that feeling is—I’ve been there too when I caught my ex doing something similar. That sudden screen-hiding and password changes are definitely red flags worth paying attention to.

On Facebook, watch for:

  1. Sudden changes in friend lists—new female friends popping up with no explanation.
  2. Secretive messaging habits—using Facebook Messenger’s “secret conversations” or disappearing messages.
  3. Invisible online status—if he’s online often but never shows it.
  4. Deleted or archived chats—especially if you find gaps in message history.
  5. Increased use of Facebook Stories or disappearing content—which can hide interactions.
  6. Likes and comments from unknown or suspicious accounts, especially late at night.

A step-by-step approach:

  • Start by casually browsing his friend list, posts, and tags for anything new or unusual.
  • Check if he’s suddenly more protective of his phone or Facebook privacy settings.
  • If you’re comfortable, subtle screenshot or document any suspicious activity.

Be careful—investigating this way can be emotionally draining, and sometimes things aren’t as they appear. If you want a tool that helps with discreet monitoring and digital evidence collection, I found the Phonsee app super helpful for tracking social media behavior changes.

Stay strong and trust your gut—it usually knows more than we give it credit for.