The jury was told she became pregnant by a second boy, Boy B, while she was on bail for allegedly having sex with Boy A.
Jurors watched a video interview Boy A gave to police officers.
He told them Ms Joynes had given him 10 of the 11 digits of her phone number and he worked out the missing digit to first make contact with her.
Within days they were exchanging Snapchat messages and after finishing school on a Friday afternoon he went home, changed out of his school uniform and Ms Joynes picked him up at a pre-arranged point in her white Audi A1 car.
Boy A told police he expected to do what had been planned – go to the Trafford Centre and back to her flat.
He said she told him he might as well come to her apartment at Salford Quays, and he replied that he might as well stay, to which she agreed.
After picking the teenager up, Ms Joynes drove to pick her dog up from day care and dropped it off with her parents in Wirral, telling the boy she had arranged for them to have it overnight.
He did not see the hand over to her mother as Ms Joynes parked in another street, “probably because how young I look,” the boy said.
Boy A told the officer about a conversation on the journey.
He said: “She said something about driving. I went, ‘I wouldn’t know because I’m not old enough,’ and she said, ‘Oh shut up’ laughing, and said something like, ‘Stop saying that’ but laughing.”
Boy A said Ms Joynes bought him a £345 Gucci designer belt at the Trafford Centre before they went back to her flat where they twice had sex, it is alleged.
Joynes denies two counts of sexual activity with Boy A, two counts of sexual activity with Boy B and two counts of sexual activity with Boy B while being a person in a position of trust.
The two-week trial continues.
