A twisted relationship between teacher Tamara Hofmann and one of her students turned deadly when the boyfriend of the older woman caught the two together and fatally stabbed the boy.

Police said Sixto Balbuena Arizona entered the house of the 48-year-old math teacher after 2 hours on Friday and met Hofmann and 18 years old high school student Samuel Valdivia naked in the bathroom. According to police reports, Balbuena punched, kicked and then stabbed the teenager with a kitchen knife. Valdivia died later in hospital.

Valdivia heartsick as friends and family mourn their loss, also wondered why the teacher invited the students in the last hours of the night.

Hofmann, a teacher from El Dorado High School in Chandler, AZ, once taught at a different school Balbuena. Balbuena, 20, Navy sailor, was arrested Tuesday and charged with second degree murder. Balbuena is held in place bail of $ 100,000.