Task: Question Answering
Input (English): Gerard lightly stroked Frank's cheek smiling in satisfaction when Frank began to purr at the light touch , " my , my Frankie , who knew you were so sensitive ? " Frank blushed before he buried his face in Gerard's chest . Gerard heard a small mouse like whisper from Frank " Frankie ? ... " 
Question: Why did Gerard lightly stroked Frank's cheek ?
Output (English): Because Gerard feels affectionate toward Frank .