Nice - when my discovery happened, the circumstances were not the same in that he came home from work at the normal time for that day, but it was past 2a.m. At about 1a.m., I'd found his old phone and had discovered text messages to the OW he had not deleted. I then went on to access his online phone bills and the evidence was all there. When he came home, I confronted him immediately and he admitted having an affair. He was in so much shock (as was I) that I could barely get any sense out of him. I still look back in amazement that after about 15 minutes of establishing the bare facts, I let him go to bed (in the spare room).
I look back now and think it was probably for the best - the tiredness combined with the shock would have prevented any rational discussion, but I do wish I'd thought more logically and asked him to hand over his phone immediately. It would have been full of evidence that he deleted in the initial aftermath i.e. photos of her that she'd sent.
I spent a totally sleepless night and couldn't get warm - my body was actually freezing cold, despite it being a warm September night. He tossed and turned all night and barely slept.
We had to wait until 2p.m the following day for our kids to go out to have the most painful conversation we have ever had. This then got interrupted on their return and we had to wait until they'd gone to bed to resume, by which point we were both exhausted again.
I wish I had phoned someone and made arrangements to have them overnight. I'd have come up with any old excuse (a D and V bug that I didn't want them to catch - anything) so that we'd had 24 hours of uninterrupted time. The interruptions in the days following were awful - it seemed as though every man jack and his wife knocked on the door or phoned us that week.
You need uninterrupted time, really you do. Please get that if you need it. Also, please realise you are in shock - real shock.
I know that some people would prefer time and space apart but I didn't. I didn't want to let him out of my sight and I needed answers.
It is not, repeat not, your fault. I understand why you are beating yourself up, all nice people do this. But if there had been any problems on his side, it was his responsibility to tell you. I don't care what anyone says, an affair might be understandable, but it is never justified. It's a crap behaviour choice.
My advice over the next few days is also - listen to what he says, but then for your own peace of mind, try to verify it. His phone will be the biggest key of all. In the early aftermath, betraying partners often downplay events, so as to minimise their culpability. They will admit to only what you can prove. He might be saying this was a drunken one-off for example, but it seems likely to me that there was some build-up to this etc. You can recover as a couple from this, but lies and dishonesty now will hamper progress, as will further revelations down the line. Try to get it all now, by hook or by crook - it really will help you, believe me.
Don't be rushed into deciding what you want to do. Listen and take your time. Please however, do post on here and we will help you.