Harper dealt with the loss of her father by using art as a place to escape to. Her natural talent came out and pretty soon public schools didn't have anything left to teach her. A charter school took over and it was clear she should go to a good college to further her fine arts education. Several colleges were interested, but all required she submit a complete portfolio. That meant she had to do some figure studies, normally depicting the unclothed human body. The female model was easy. Her mom volunteered, as long as the end product wouldn't look too much like her. But where to find a man she was comfortable being in the room with while he was naked? Bob had been her mom's best friend ever since her father died. Harper had been his pal forever. When she asked him to model for her, she couldn't understand why he was unenthusiastic about it. What was the big deal?
When her mom explained Bob might be embarrassed by a normal male reaction, Harper said he was being silly. She more or less browbeat him into posing for her, and her mother's prediction came true. She coudn't draw him THAT way. Museums just don't depict erections. Something had to be done. Addressing that issue was what changed all their lives forever.