8. He or she suddenly doesn't want to hang out with your friends
Social interactions are important to maintain a healthy relationship, especially with friends, be they your own or your partner’s. Whether or not they got along with your friends in the past, if you all hung out before and suddenly your partner no longer wants to, that’s a suspicious change you should keep tabs on.
Your friends reflect who you are, but they are also very perceptive when it comes to the members of their social circle. If your significant other starts avoiding social opportunities with your friends, they may be doing so out of fear that your friends will see through their deception and discover their cheating. Or, they may simply not want to be around people who remind them of you as it will only increase their guilty feelings or resentment. Either way, it’s not a positive sign when your partner is limiting the time spent with your friends.