Former teacher’s aide Chrystina Delrosario has been sentenced to three years of probation and ordered to register as a sex offender, reports KGTV. She pleaded guilty to charges stemming from sexual encounters with a 15-year-old male student at a San Diego-area school for juveniles who have committed crimes. On one occasion, Delrosario and the student had sex under her classroom desk while another male student helpfully served as a lookout, adds Patch.com.