Women tend to do these things when their lives aren't at their best. Whether they need some excitement or for someone to see them as an individual (rather than a wife or mother) and to see them as special and attractive. While you may have been perfectly happy with the way things were, she may not have been - particularly if she is a stay at home mum. You say you have a warm loving and affectionate relationship, but what about those long hours you are at the office? Is she left alone with nothing better to do than look after the children and clean the house? That can sap your soul and make a little flirtation the most exciting thing in the world. Think back to the excitement you felt when you and she got together at first - the thrill you'd get when she called you etc. She's just trying to replicate those feelings. It makes washing everyone's dirty underwear a helluva lot more exciting. But its just a little thrill - it doesn't mean she isn't happy with you or that she doesn't love you or want to be with you. It means she needs more than she has in her life, something to stimulate and challenge her. It probably has very little to do with your actual relationship, but she may feel that her life is somewhat stale or that she is frumpy or unattractive (motherhood'll do that to you) and if she's not working then her confidence is probably quite low. You need to encourage her to find other ways of boosting her ego and self esteem. If she feels better about herself then she will be less inclined to look for this type of distraction. Take some time apart and then meet on neutral ground to discuss things - away from the children and the home. Then really talk to her, and listen to everything she has to say too. You both have to be completely honest if you are to put things right, and you must put it behind you too - as Bob say, no throwing it back in her face. I wish you well, Karen x