According to his moral calculus, his having married Connie entitled him to one last grand use of his sexual license, which she'd granted him long ago and never expressly revoked. If he and Jenna happened to click in a big way, he would deal with that later. (3.5.37)
"You did the worst thing you could possible do to me," he said. "The worst thing, and you knew very well it was the worst thing, and you did it anyway. Which part of that am I going to want to think back on?"
"Oh, I'm so sorry," she said, weeping afresh. "I'm so sorry you can't see it the way I see it. I'm so sorry this happened."
"It didn't 'happen.' You did it. You fucked the kind of evil shit who would leave this on my desk for me to read."
"For God's sake, though, Walter, it was just sex."
"You let him read things about me you never would have let me read."
"Just stupid sex four years ago. What's that compared to our whole life?" (3.6.137)