Kwanten suggested that Paquin and Moyer's child will be very lucky to be brought up by such wonderful people.
"They have a real lust for life. Yes, they're adults, but they're both very young at heart," the actor told Us Magazine, adding: "I would love to be raised in that household!"
Kwanten added of expectant mother Paquin: "Anna's excited... she's got that positivity, that radiant glow. She's amazing!"
Paquin and Moyer officially announced in April that they are expecting their first child together to be born this autumn.
Moyer has since said that the prospect of becoming a father again is "amazing".
The True Blood pair wed in California in 2010.