One of the first signals, in which you need to consider is the distance from each other. Perhaps the fact of physical proximity with another person does not have. But a permanent partner is becoming not interesting. If earlier the family had some lovely tradition, such as breakfast in bed or walk in the park on weekends, and now her second husband ignores it too disturbing "bell."
The classic signs of change most people are familiar: a reluctance to talk on the phone in the presence of a partner, the late calls and sms, and the absence of a response to a question about the interlocutor. To dispel any doubts, you just need to look at the phone, read text messages and check unfamiliar number. However, a girl named Leroy can be written in the contacts as a friend Valera and provocative posts may be removed. Therefore, this test can not give anything.
Much can "say" and her husband's clothes. In his trouser pocket can find a love note on the collar shirt - traces of lipstick and wallet - a check for the purchase of jewelry. Therefore, periodically review things partner, suddenly there is something interesting.
If the husband has a mistress, then surely it been in his car. It is necessary to carefully check the car. This can be a hair rolled under the seat lipstick or even ash from thin cigarettes. Of course, all the signs of infidelity indirect, but nevertheless, they provide a reason to think.
No need to lose sight of the computer and the chosen one. Check the sites to which he came, see the page in the social network - there may be a lot of interesting things.
You can try to "catch" the husband or wife at his word. It's like a joke:
It - My dear, when I die, you'll give my car a new wife?
He - What do you mean? She and rights do not.
You can try to come to a husband or wife in the office, without warning. The probability is small that you can see the fact of treason, but doubts about the loyalty will be either strengthened or dispelled.
The best way to learn about the change - is to hire a private investigator who can provide proof of fidelity or infidelity "second half".