How to assess:
- Feeling like something is wrong: trust you intuition. If you think something is wrong, pay attention. Unless of course you are one of those apt to find a problem everywhere.
- Constant privacy: if they start to need more time “alone” to surf the net or to go out with friends or to just be without you and they did not do it before, something is up.
- If they state that you are “just friends”: if suddenly you become just friends then something is on the back burner. They just have not had the courage to break off with you yet, since the other thing is not for sure yet.
- I love you so much but not “in love” with you: this is the time to run the other way if things are not so deep. If you care then you have to figure out what is going on.
- More showers than usual: Cheating people will often pay close attention to their grooming habits. Dress better, make sure their hair is perfect. There is a certain amount of normal in this but if it changes suddenly, pay attention, something is up, they are impressing someone.
- Late evening work hours: a certain amount of late at work is reasonable but if starts up suddenly and keeps getting longer and more often then they are seeing someone else.
- Needing space: when you are a couple, space is limited but when it is demanded when it was not before, something is up.
In general, the rule of thumb is to pay close attention if things change suddenly in areas that were normal for the two of you. Habits changing or attitudes even. If they get angry too quickly lately or never show up on time when they say they would. When you call they do not pick up.
Refrain from being paranoid but do not be stupid.