Few things can end a marriage as quickly as infidelity. If you have ever suspected your spouse of seeing someone on the side, you probably understand all too well just how devastating this can be. Often, spouses who have suspicions about their significant others have reason to feel the way they do. In many cases, unfaithful spouses exercise some of the same signs.

Thus, if you believe your spouse of committing adultery, know that the following signs may indicate that he or she is doing so.

Sudden changes in appearance

Is your normally low-maintenance spouse suddenly working out obsessively, tanning or investing in expensive clothing, skin treatments or accessories? While this is not necessarily a sure sign of an affair, it could potentially indicate that he or she is trying to appeal to, or draw the interest of, someone other than you.

Increased periods of unreachability

Has your spouse stopped answering your calls, or returning them promptly, when he or she is generally highly responsive? This, too, could signify that something is amiss in your marriage, particularly if these periods of “going dark” tend to coincide with your spouse working late, taking business trips or what have you.

Friends who increasingly avoid you

If friends you and your spouse share have suddenly begun to avoid spending time or talking with you, this could be a potential sign of infidelity. In many cases, the person whose spouse is stepping out is the last to know about his or her partner’s indiscretions. That means that your mutual friends may know first and avoid you because they feel awkward or uncomfortable knowing what they know.

While these signs could all indicate potential cheating, they do not necessarily mean with certainty that your spouse is being unfaithful. However, the more signs you see, the more likely you are to be correct in your suspicions.