John told about his sore chest

"So, how was your week, John?" Dr. Valentine asked.

"Good." John replied with a smile. "I did everything you told me and could hold back cumming for around 10 minutes, perhaps a little less."

"That's a good progress." She commented also putting on a smile. "When you continue with your good work, you'll soon last long enough."

"Yeah, I hope so." John shifted his weight a little before he addressed something clearly uncomfortable for him. "But all the playing with my chest made it feel sore."

"Can you show me?"

John took off his shirt. His chest was reddened. "And the rubbing of the shirt causes my nipples to get hard." John blushed as he said that.