The relationship between Dylan and Kelly was one of the most enduring, angst-ridden on Beverly Hills 90210. Their off-and-on relationship spanned for much of the series' 10 seasons.
Dylan and Kelly have been friends since childhood along with Steve Sanders. Kelly harboured life-long feelings for Dylan.
In the summer of Senior Year Dylan and Kelly had a summer fling while Dylan's girlfriend and Kelly's best friend Brenda was in Paris. Kelly was often the voice of reason in their relationship citing the pain they could cause Brenda if she found out but their feelings for each other always got the best of them. When Brenda returned from Paris it became difficult for Kelly to watch Brenda and Dylan together. Dylan and Brenda eventually broke up due to new found differences. Kelly later checked with Brenda that Dylan was free to date whoever she pleased and Brenda agreed. Dylan and Kelly then started dating. Kelly then pushed Dylan to tell Brenda about his fling and he did. Brenda admitted to having a fling also and Dylan and Kelly continued their relationship. Dylan and Kelly went out on a date and while there ran into Brenda on her date. Seeing Dylan and Kelly together made Brenda feel angry and betrayed. Dylan and Kelly later told Brenda that it was her that Dylan had a fling with. Brenda being angry severed all ties with the couple. Kelly later reached out to Brenda and their friendship was repaired. The two girls later told Dylan that he would have to choose.
Meanwhile Jack McKay was realised from prison. Jack later threw a party to celebrate his release. Dylan invited both Brenda and Kelly but only Kelly attended while at the party Dylan and Kelly went for a swim in the pool and Dylan told Kelly that he chose her. Dylan confessed to have harboured feelings for Kelly for a long time.