"I love my kids beyond anything," the True Blood actor, 42, told Us Weekly of his two children, Billy and Lilac, from previous relationships. "They're the best things ever, and having two more is just going to be even more crazy, but that's cool!"
The couple announced in April that they were expecting their first child, and Paquin, 29, is due in the fall. They wed in 2010 after getting engaged the previous year.
True Blood airs Sundays at 9/8c on HBO.