I missed them all.
I guess I am just a dimwit.
But here are some that should have been glaringly obvious.
He used to go out one night a week with the boys. Then, suddenly he INSISTED on going out three nights a week, claiming he was stressed by new job and needed to blow of steam with the boys.
He was not with the boys. There was no discussion about whether or not I approved.
He was suddenly Leaving earlier for work.
Coming home later.
Coming home Smelling of perfume.
The proverbial lipstick on his color. He claimed it was a red pen. It was the permanent stain type of lipstick, so I believed it was a pen stain and actually used a stain remover and washed it for him. 
I don't wear lipstick, so I was clueless about permanent stain type lipsticks.
He suddenly bought a new car. One that was more expensive than the usual type he would buy.
He suddenly needed an Ipad (later found out it was so he could stay in touch by email with younger OW)
Found out a credit card statement was going to his office instead of home.
When, I questioned him about it, he became angry and defensive. I dropped it.
Saw cash removals from bank account. Saw expensive restaurant lunches on his other credit card. He said the money and the lunches were used to entertain potential clients.
Later after dday, I found a hidden bank account and a second hidden smart phone.
He was irritable almost constantly. I thought it was the stress of his new job.
He was annoyed if I greeted him at the door and wanted conversation, when he came home. He would say he was talked out.
Later I found he would spend hours on the phone talking to OW.
He would say he needed to go to home depot to get home repair supplies, and would be gone four hours. Later learned he was with OW.
He would buy home supplies, but stopped doing anything around the house to repair things.
He would take cell phone calls in the garage or in the backyard.
The OW was taller than I, so the passenger car seat was always moved to the far back position.
I noticed this and questioned him, but he said it was his tall dad who moved the seat, when they went for lunch.
The car seat smelled like cologne. Couldn't quite pin down if it was a male or female scent. He again attributed to his father's cologne. It was not.
After Dday, I found strands of the OWs hair on the floor and tangled around the head rest.
He picked fights. After one fight, he asked me for a divorce.
I said fine, if that's what you want, and he changed his mind and tried to make up. We did because I was still clueless.
He once picked a fight and then packed his cloths and stormed out of the house overnight.
I later learned he went to see the OW while her husband was away on business.
His boss called me at home, looking for him, saying he could not get in touch with him about something important and asked if I could. I couldn't.
My husband later said his cell was turned off because he was with a client. He was with OW.
His assistant called and said he suddenly could not get him on his cell.
His father would call me and say he suddenly could not reach his son on his cell.
I would call and he would not answer his cell, as he normally did.
He once called me on my cell and when I answered, he sounded confused, and stammered and said, he meant to call a client, then hung up abruptly, did not even ask how I was, as he normally would.
I later learned, that he had meant to dial the OW, but had dialed me by mistake.
A call from his second phone showed up on my home caller ID, it had his name on it but wrong phone number for his usual cell.
When I showed him the caller ID he said "Well it must be some other guy with the same name, but see the number is different.
How stupid was I to be clueless, until he was outed anonymously?
Pretty stupid, right?
