Shortly before D-Day, I found a receipt for a pizza place we never go to for like $30.
I questioned him, because it was a place near OW's. He said OW (a work "friend") recommended it so he got lunch there one day - ordered a pizza, didn't like it, so he ordered a pasta dish instead.
I knew it was total bullshit - the bill was that high because he got food for 2 people, but I was still in my fog and let it go... rationalized it by saying it was ok to treat a friend to lunch once in a while.
To this day he will still not admit to their "date". I don't care about that much anymore, but I was supplying his lunch money and I'm pissed he spent it on her.