Joel Tennyson
From Ben10versepedia
Joel Tennyson made his first appearance in "My Big Fat Alien Wedding". He is Grandpa Max's nephew and Ben, Gwen's cousin. In addition, he is a member of The Plumbers like his uncle, Max. He made a relationship with an alien spiece known as the Sludgepuppies named Camille Mann. There has been a history of Sludgepuppies and The Plumbers at war for many years. Both Joel and Camille have hopes that there will be truce between each other afater they engage. Unfortunatly, there were wedding crashers and they were Mr. and Mrs. Mann, Camille's parents. Afterwards, the marriage continued successfully thanks to the help from the Tennysons.
see also: Tennyson Family