He and his ex-wife, Judith, are Jake's parents, and Alan is possibly the biological father of Judith's second child, a daughter named Millie Melnick.
After losing his house to Judith in the divorce, he moves in with Charlie.
Their relationship goes into season seven where Melissa wants to move into the beach house with Alan, Charlie, and Chelsea.
Alan is happy to live with Melissa at first, but eventually Melissa and Chelsea start taking over the house, resulting in Alan and Charlie staying at a hotel. Evelyn tells Chelsea about Melissa's short lived romance resulting in the girls getting into a fight, and Melissa moving out.
He is a womanizing bachelor who tended to abuse his younger brother Alan, whom he loved dearly, although he would have never admitted it, and usually took pleasure in any misfortune or trouble he runs into.
Charlie was a jingle writer and a children's music performer under the name Charlie Waffles.
Charlie spent his days partying, sleeping, gambling, drinking alcohol, womanizing and wearing bowling shirts.
Walden Schmidt replaces him as the new owner of the beach house, a recently divorced internet billionaire.
In season eleven, Jake moves to Japan and leaves the series, so to replace "the half-man", Charlie's long-lost-daughter moves into the beach house after looking for her late father.