text: I am told that not telling the truth is the most common attitude.\n\nit is a common reflex in order to protect the official relationship.\n\nDo you little research (pockets, mobile phone, emails etc), if that is important to you. You can also hire a private detective, but that is expensive. Otherwise, just probe some good friends naively and see what they say/ know.\n\nGood luck, it is not pleasant to suspect your partner is having an affair. On the other side, knowing the full truth is not necessarily better. I have been there.\n\nAll the best.