You can imagine the scene would start off innocently enough, especially if there were lots of kids in and out of the house.
You find a mobile phone lying in a drawer or under a bed and it briefly crosses your mind who it might belong to.
In our house, there are at least three or four old handsets we keep meaning to donate to the Jack & Jill Foundation (and we will), one kept for mountain pursuits (don't ask) and everyone else has their own.
So, coming across yet another is hardly odd.
Would there be a glint of suspicion though, and would it prompt you to have a quick glance at the messages and try to work out its owner?
Well, it seems women would be much more inclined to, according to recent research by a university which found that wives spied on emails, texts and phone records far more than their husbands.
Of course, 'spied' might be pushing it. Being curious probably covers it for most of us.
By all accounts, that seems to be how Yvonne Keating discovered hubby Ronan's, er, new friend, Francine Cornell -- a mobile she came across which she didn't recognise.
She may well have wondered whether a pal or a child's friend left it behind after a visit? Would you have peeked at the texts?
Well, she did, apparently, and Ronan quickly found out 'when you say nothing at all' isn't much good when you leave it for all to read on a phone.
When Tiger Woods' prolific extra-marital activities were discovered it was because wife Elin found a mobile with messages that contained nothing about his handicap or sand wedge and lots to do with blonde cocktail waitresses.
Some 14pc of married women admitted to secretly reading their husbands' emails, 13pc their texts and 10pc went to all the bother of looking up web- browsing histories.
Are women naturally more suspicious then men? Some blokes wouldn't recognise their wife's affair if her lover slapped him in the face, it's true, but in love, as in life, it's the details that trip you up.
We don't know how long Ro's relationship has been going on, but clearly long enough to require the effort of hiding it.
Infidelity expert (yes, of course she's American), Ruth Houston has even written a book with 829 'telltale signs' that your husband is having an affair. I'm guessing that finding a strange mobile is near the top.
David Beckham found that stray texts can catch you out when Rebecca Loos smugly showed her mobile phone to a Sky television camera ... and the world.
Other alarm bells that wives cotton on to include a sudden increase in the number of conferences her man is asked to attend or how the number of nights 'working late' have risen. His skills have rapidly become invaluable and he's constantly required to disappear out of the country at short notice.
Houston recommends offering to join him as a surprise to gauge the reaction. On the other hand, if you're wrong, you get to wander the streets of Birmingham while he's actually doing business. Of course, what inevitably gets cheating spouses in the end is complacency. If an affair has been carrying on for a while, you get tired of all the covering up, the secrecy, the neurotic juggling and are apt to be careless, especially with phones.
In Ireland we're renowned for virtual saturation of the mobile phone market, but we're in the ha'penny place compared to Italy, where owning two or three handsets is the norm, and a report by leading private investigator Miriam Tomponzi, shows a staggering 87pc of affairs are discovered that way.
Happily, she offers tips for would-be cheaters: "You must cancel immediately any message from your lover which could give the game away.
"It is hard to cancel a beautiful message, so you could have another mobile phone in a secret place and send them to that". And that's not enough.
"You must practise and prepare yourself for when you receive a phone call from your lover in front of your husband or wife ... in front of a mirror if you have to.
"You must pretend that a sister, mother or brother has called you and act normally."
Advice, sadly, too late for some.