Harriet was very confused. She had really no idea what was happening. "But... but Ms Castellesi I just wanted..." and then her protest were muffled by the huge breasts that were thrust into her mouth. By the teacher's words it seemed that Harriet had volunteered for the role of O...<em>how did that happen?</em><br/>But Harriet only had seconds to think before the mask was put on her face. She couldn't see a thing but she suddenly felt the huge bulge on the other<em>volunteer</em>. She tried to do as the teach said, get into the role. Harriet would be in the role of the submissive O. So she started by running her fingers over the hardness that almost threatened to fall out of the thong. She used her nail to trail along the length of the cock, it felt enormous, far bigger than her own and Harriet knew that she'd never get her hands around that monster. She stood close to the other volunteer and then she kissed her on the neck and let her tongue gently lick her. She gave her small kisses that travelled up towards the other girl's mouth until she found the mouth and let their tongues play. At the time she reached the mouth, her hands had pulled away the troubled thong and she played with the balls with one hand while she slowly stroked the length of the marvellous cock with the other.