A spouse's secretive behavior is often the first sign that leads to suspicions of infidelity. An unfaithful spouse typically shifts the focus onto her partner when being asked simple questions about daily activities or upcoming plans.
A sudden change in neediness can also be a sign of a cheating spouse. A shift from overly needy behavior to overt independence is often an indication that someone else has filled the role that was once filled by the spouse. Changes in demeanor are another sign; if a spouse is notorious for getting angry over the little things, and that suddenly stops, it may be time to wonder why that spouse no longer cares.
These signs are not guaranteed indicators of unfaithful behavior, as each one can easily be misconstrued or taken out of context. Spouses who feel their significant others may have cheated should approach the situation with extreme delicacy, as unwarranted accusations have the potential to spoil an ultimately healthy relationship.
Open the lines of communication by expressing changes that have become apparent. Avoid blatant accusations in favor of questions such as, "Is there anything you'd like to tell me?" and "Are you sure you're being 100 percent honest with me?"