Actors Anna Paquin (L) and Stephen Moyer attend the "True Blood" panel at San Diego Convention Center on July 14, 2012 in San Diego, California. Credit: Chelsea Lauren/

He's already a proud father of two, but Stephen Moyer will have two more reasons to smile when his wife, Anna Paquin, gives birth to twins later this year -- as Us Weekly first reported in June.

"I love my kids beyond anything," the actor, 42, told Us at the Playboy and True Blood party in San Diego, Calif. July 14; Moyer has 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!"

Though Paquin, 29, skipped the star-studded party, "she's good," Moyer assured Us. "She's in bed and I am going to be there very soon myself!"

Michael McMillian, who plays Steve Newlin on the HBO vampire drama, said the entire cast has "been impressed" with how Paquin is handling her pregnancy. "The show is taking great care of her, and I think she's probably really happy that she has some time off now to focus on what's to come."

McMillian, 33, added that "Stephen is already a terrific father and they make an amazing couple. Anna is really excited, as any expectant mom is. I think they're going to be pretty cool parents."

The couple, who wed on August 21, 2010, might want to seek advice from costar Sam Trammell, 43, who welcomed twins Winston and Gus with girlfriend Missy Yager in August 2011. "There's something in the water over at True Blood," McMillian joked.

True Blood -- which also stars Alexander Skarsgard, 35, Rutina Wesley, 33, Ryan Kwanten, 35, Kristin Bauer van Straten, 45, and Joe Manganiello, 35 -- was recently renewed for a sixth season by HBO.