|Piper Halliwell and Dan Gordon|
Piper breaks up with Dan in order to have a relationship with Leo.
The relationship between Piper Halliwell and Dan Gordon was a major storyline in the second season of Charmed. Although it only lasted during that season, it was one of the most significant love stories of the series.
After some time, Dan found himself attracted to Piper, but didn't want to show his affection due to fear of rejection. Piper soon found out and genuinely returned his feelings. Soon they became a couple, though Dan sensed tension whenever Leo Wyatt, her ex-boyfriend, was around. Despite honesty in their relationship, Piper found herself unable to share with Dan the knowledge about her being a witch who often had to fight dark forces.
When Piper almost died from Oroya Fever, Leo healed her and lost his wings. Piper felt responsible for this and took him under her care, a fact of which Dan was jealous. Piper eventually realized her true feelings for Leo and reluctantly broke up with Dan to give their relationship another try.
He tried to find information about Leo's past, and was surprised when he only found the identity of a man who died in World War II. In the season finale, Piper wished for Dan to move on with his life, and an eavesdropping genie granted it, giving Dan a job in Portland but consequently making him age in a matter of hours. Piper and Leo then revealed their true identities, which Dan did not take well even after his youth was restored. Piper then wished for Dan to forget what he knew while he was old and to truly move on without consequences.