Poor Kathy. That Gavin has really done a number on her head. She doesn't know right from wrong anymore. I can understand why Ian would throw her out after her admission, though I think he might have been a little more understanding himself. After all, she did come clean instead of going through with the plan. If she really was intent, she could have kept quiet and he'd never know until it was too late.
At least Pam is now taking the next step to understanding Les.