Chat Using Fake Profile
No one said that figuring out if someone is cheating on you on Facebook would be easy. Put forth some effort and set up a fake Facebook account. So, here is another suggestion how to tell if someone is cheating on you on Facebook. Make it convincible and engage in the conversation with your partner. This way you can see how your partner acts when he talks to unknown people over Facebook. If your partner starts flirting and crossing the lines of polite conversation, then you should know it isn’t their first time. Keep the conversation going for some time to see how far your partner is willing to go.