Facebook messenger is private and is designed with privacy in mind, making it difficult for people to see who other people are talking to. If you need to know who somebody is chatting to on messenger and what they’re chatting about, installing a monitoring app is the best solution. There, you can monitor a friend’s activity log, Facebook posts, who they’re talking to, and what they are talking about. You can install the app on their device and then monitor it from yours without them knowing.