It was Moyer who let it slip at the premiere of "True Blood" season six in Hollywood that the kids' names were Poppy and Charlie, reported Aceshowbiz.
The 43-year-old father of four first said his 10-year-old daughter, Lilac, from a previous relationship was leaving for sleep-away camp this past weekend. He went on dishing that he and Paquin would spend Father's Day "hanging out with Charlie and Poppy."
His actress wife chimed in that she planned a "surprise" for her husband.
Paquin, 30, gave birth to the twins last fall. The babies are her first children. They join half-brother Billy and half-sister Lilac.
Paquin and Moyer were married in August 2010. They announced the pregnancy in April 2012 but did not reveal that she was carrying twins. It was their "True Blood" co-star Sam Trammell who actually let it slip that they would juggle two babies.