The two formed an interest in one another through a mutual class at Degrassi Community School. Though Jane tried to brush off her attraction to him at first, the two began an affair while Jane was still in a relationship with Spinner Mason. They carried their affair on in secret for about two weeks, until Holly J. Sinclair encouraged Jane to break it off with Declan. Several months later at a year-end pool party at the Coyne house, Spinner overhears Holly J. and Jane talking about Jane's affair with Declan. Angry and heartbroken, Spinner permanently ends his relationship with Jane and punches Declan.
Season 9In Close to Me, Jane and Declan are put in charge of the school play. Jane decides to invite Declan to Spinner's housewarming party. At the end of the party Jane and Declan come up with a subject for the school play. Declan offers to walk Jane home, but she rejects. Declan invites Jane to work on the play with him at his house and Jane excepts. Declan gives Jane a tour of his house and even though he knows she has a boyfriend, Declan kisses her. The next day, Declan walks into The Dot and sees Jane and Spinner together. He asks Jane if she wants to study at his house tonight and she says yes.
In Wanna Be Startin' Somethin', Jane and Declan continue their hidden rendezvous. Holly J. accidentally hits Declan's car on the way to school, but he is cool with it and says it's fine. Holly J. begins to crush on Declan. She catches Jane and Declan kissing and confronts Jane. Jane eventually breaks it off with Declan, feeling bad about cheating.
In Degrassi Takes Manhattan, Spinner over-hears Jane talking to Holly J. about her affair with Declan. She confesses that the two had sex and her relationship with Spinner is ended. Spinner then attacks Declan in anger. Declan and Fiona invites Jane and Holly J. to Manhattan. Later, when Jane finds out about Spinner's relationship with Emma, she forces Declan and Holly J. to go with her back to Toronto to stop their wedding, using one of Declan's dad's cars. Though initially confused, the two decide it's best to stall and let the wedding happen. Jane then steals their car.
In Love Lockdown (1), Declan wins the Grundy award for the play "Space Awakening" for help directing the play last year. Before dedicating the whole award to Holly J. in an attempt on winning her back from her relationship with Sav, he mentions that Jane Vaughn should be receiving this award along with them, but she's off to bigger and better things at Stanford.
- Start Up: Close to Me (904)
- Broke Up: Wanna Be Startin' Somethin' (906)
- Reason: Jane realized it was wrong to cheat on Spinner with Declan.
- Spinner, Jane's boyfriend at the time, punched Declan once he found out about the affair.
- Before it was revealed to everyone in Degrassi Takes Manhattan, Declan, Holly J., Jane, and Bruce (in the Degrassi Mini Good Times) were the only ones who knew about the affair.
- They called their affair "homework" around Spinner.
- After their relationship ended, Declan went out with Holly J., Jane's best friend, and there was no jealousy between the two.
- Jane claimed Declan made her feel like a "real woman".
- Jane's last line was said to Declan and his ex girlfriend Holly J. ("I can't wait to find out...let's go.")
- They were both members of the Degrassi Drama Department.
- In a deleted scene from Waiting for a Girl Like You, Declan asked for Jane's permission to ask out Holly J.