About Dumbledore 's absolute trust in Severus . And then Tonks lied . She pretended that she herself did n't know the reason why Dumbledore trusted Severus . ' But Dumbledore swore he was on our side ! ' said Tonks urgently , trying to convince herself more than anything .
According to the above context, answer the following question.
Why did Tonk lie to herself about Severus ?


Tonk lied to herself because she wanted to believed in Dumbledore .