A former Vernon, B.C. elementary school teacher is on trial this week for an alleged affair she had with a young student that spanned years and comprised hundreds of encounters.

The purported relationship took place from 2002 to 2005 between 45-year-old Deborah Ashton and a young man who was just 12 years old at the outset.

Ashton, who has two children of her own, allegedly had roughly 200 encounters with the boy, many involving sexual intercourse. She was arrested in 2008 and charged with counts of sexual assault, sexual touching and touching a person under the age of 14 for sexual purposes.

On Thursday, a friend and teammate of the alleged victim testified he saw Ashton and the boy go under the covers while staying in a cabin-like accommodation on a basketball trip.

"I asked them, ‘What are you doing?'" he said. "They didn't reply and I just left it."

"When I woke up in the morning they were side-by-side."

The alleged victim, who is now 21, has testified he was not forced into a sexual relationship, though he would have been too young to legally consent.

With a report from CTV British Columbia's Kent Molgat