The prosecution told the jury the relationship started because the accuser developed a crush on Dudley.
Richard Vance, prosecuting attorney said, "In fact, one day, she even tells him that she thinks she's attracted to him, and the evidence is going to show, at that point, is where it all began."
Vance says the 2 sent over 500 electronic messages to each other last summer, and talked on the phone.
Dudley's defense lawyer, Jeff Haas, says that doesn't prove anything.
"Donald Dudley is a teacher who helps students. Donald Dudley is the type of teacher who goes out of his way to help students and tutor students, and that's what initiates this whole thing."
From the stand, the accuser told the jury the 2 first kissed after a trip to the Caldwell Zoo.
She said, "On the way home, he pulled over behind the rest stop area. He looked at me and said, 'Okay, you want to kiss me. Kiss me.' I was shocked because I didn't really think he'd do that, and I didn't do it at first. Then he started to pull off. Then, I stopped him and kissed him."
From there, the girl says Dudley began coming to her house to help train her pet bird.
In her room, she says "We would kiss, and he would touch my pelvic area and my breast."
Then, she says, she started going to Dudley's Tyler home to clean it.
"When I went over to his house for the 2nd time, we had sex. I can't remember how it started. We started kissing, and we went into his room, and got onto his bed. We had sex," said the victim.
It's that accusation that landed Dudley in the Smith County courtroom yesterday. His defense attorney don't deny the 2 had formed a friendship, but they say Dudley never had sexual contact with the victim.
"In today's world, often times it's not inappropriateness that will get you in trouble. It'll be the appearance," said Haas.
Regardless of the outcome in this trial, Dudley's troubles are not over. He's facing similar charges in Henderson County.
That trial won't begin until sometime this summer.