Would it be possible that they could be cheating but still act like they always have? Or will they have a noticeable change in the way they act?
Most Helpful Girl
From the cheating situations I have witnessed over the years, it depends on what is going on but, yes, usually there will be signs. One friend had the classic things happen, like finding another woman's earrings in the car she shared with her husband. A boss of a friend, a man in his late 30's, all of a sudden was dressing a lot better and lost weight. He ended up leaving his wife for the woman he was cheating with.
So, to me, if your partner is all of a sudden taking better care of themselves and has changes in their habits, like spending a lot of time away from you, not answering your calls and texts when they normally were good at it, it could be a sign but it would also have to be combined with the two of you being emotionally distant. For instance, not having sex very often, not talking like good friends, already not being people that hung out often. Some people can wake up and want to improve themselves without it being a sign they are cheating.
The friend of mine who found another woman's earrings in her car knew deep down something was going on, but she did not want to face it. Gut instinct is valuable. We were all out on a weekend retreat for work when she finally snapped and we realized she knew he was up to something but had been denying it. She was trying to call him (this is back before cell phones) on a land line and couldn't reach him and blew up saying that he must be with his girlfriend. We were shocked. I think it still took another 6 months or so before she left him.0