I had no idea at all, and it had been going on for 3.5 years!
In the months leading up to his confession his behaviour at home was horrible, particularly to the DC, and it was after yet another evening of vile, irrational behaviour that I finally beat the truth out of him. I had no idea what was coming though. I didn't even recognise her name at first, the period of mentionitis had been so long
As I didn't know what was behind it all, my only real line of questioning was "What the hell is going on? Why are you being like this?" and not being fobbed off with attempts to blame it on some kind of existentialist mid-life depressive claptrap.
The only thing that changed over the period was the time he came home after a night shift - put down (by him) to no longer being 25 and taking longer recover sufficiently to drive home - and then flaking out on the sofa until the DC came home (so as not to have to look me in the eye, maybe).
A friend who'd been through the same asked me if he could be having an affair and said no, not his style, at all.
And you think you know someone.
Our marriage is failing now because despite all his promises to change and claims to love me, he is still weak, secretive, unwilling to tell me the honest truth and to face all the unpalatable consequences of his acts 