Wallace cornered Pamela asking if William was the father of her baby. Not that it was going to make Wallace break up, but he was going to stop believing that his father was Josias.
However, Pamela was not sure about that and felt that Wallace could break up and leave her if she confirmed that the damn father was the brother of a girl that Wallace still felt some admiration for.
So, she violently denies it. "No! The father is Josias, Wally, you have to believe me!"
"Look, when somebody says vehemently 'you have to believe me', it is because the person is lying." Wallace philosophizes.
"I'm not lying, it's...