9 Ways to Find Out Who Your Boyfriend’s Partner Is if You Get the Feeling He’s Cheating

2. Look for a girl whose activity matches his on Facebook.

“The girl who kept commenting on his posts was the one he was seeing.” In some cases, boyfriends were cheating on girls and communicating secretly with their partner on Facebook. If you find someone who seems to be overfriendly with your boyfriend, gently ask him, “Who’s this?”