Already father to three adorable children, Ben Affleck is eager to continue procreating with his wife of seven years, Jennifer Garner.

Unfortunately, the Butter actress, 40, says her childbearing days are over. "I am not pregnant right now," Garner told Ellen DeGeneres on the comedienne's eponymous talk show (airing September 27). "I plan to be done. But my husband is kind of a wonder sperm kind of guy."

"Good to know," DeGeneres, 54, laughed.

"You never don't know," Garner responded. "You just have a look at him!"

Her husband's virility aside, Garner admitted that looking after three children is proving to be a challenge. (She and Affleck, 40, are parents to daughters Violet, 6, and Seraphina, 3, and son Samuel, 7 months.)

"I mean, they didn't pee in my eye. I don't know if it's because he's a boy. I don't know if it's because he's my third and I forget that I have him," the West Virginia-born actress admitted. "You know you're just dealing with two and then you think, 'I put a baby down. I swear I put a baby down somewhere.' And you kind of walk through the house. 'There you are!' He's just happy as can be."

Garner added that Samuel "is so chill and mellow. . . He's perfect right now because he doesn't move. But he sleeps pretty well. He reaches when he sees me and he laughs a lot. He thinks I'm super funny. What more do you want?"

This article originally appeared on Usmagazine.com: Jennifer Garner: Ben Affleck Has "Wonder Sperm"