LONG BEACH, Calif. (KABC) -- Former San Pedro High School substitute teacher Michelle Yeh appeared in Long Beach court Friday afternoon facing charges of sex-related allegations involving teenage boys.Yeh looked at the 15-year-old boy on the stand as he told the court about alleged sexual acts with his 28-year-old substitute biology teacher.One incident he testified happened in his bedroom."We started having sex on the bed, but it was making a lot of noise, so we laid down on the carpet," he said.The boy, not being identified because he's a juvenile, alleged Yeh bought him an Xbox 360 and gave him money for things, including marijuana.Prosecutors allege there were more than 70 text messages between Yeh and her student.The boy is one of four alleged victims testifying in a Long Beach courtroom. Yeh plead not guilty in August to felony charges, including oral sex and unlawful sex with a minor under 16 involving two boys.She's also facing misdemeanor charges involving two other teenage boys.Yeh is in custody after allegedly violating a court order last month by texting one of the alleged victims.The prosecutor asked if Yeh had texted him and he said no, and stated he had never met Yeh before.If convicted, Yeh could face up to nine years and eight months in prison.