The first part explains why the second part happened, it's wholly relevent.
The entire scandal is a scandal to be sure. That he cheated on his wife with an intelligence operative and whatever happened beyond that is a problem and needs to be investigated and dealt with
But this thread was about him cheating on his wife full stop. He could have cheated with anyone else and it would not have been a problem. The cheating wasn't the problem, it was who he cheated with and what happened downstream