The rumbling noises he made encouraged her.  She wrapped as much of his cock as she could in her plump lips, pumping away at his head, making wet slurping noises.  This was the first blowjob she had ever given and she had never expected it to be with a towering monster with an arm-sized cock but her very life and sanity depended on keeping him happy with her.  She was good at making people happy; she just had to adjust to the circumstances.  Sweating under the strain, she continued to work his cock.