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During tonight's sitdown with Jay Leno, Ben Affleck says that wife Jennifer Garner misspoke when she said that he had 'wonder sperm,' revealing that what she actually intended to say may have been even worse.

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"What she meant was 'wonder member,'" Ben said sheepishly. The Argo actor/director continued to drive the point, saying, "I have a 'wonder piece' -- a 'wonder johnson' ... I'm trying to do it on TV. You know what I mean? It's a PG [show]."

Jennifer made the comments during an interview on The Ellen DeGeneres Show last month. The comments circulated so quickly that they made it back to Ben before his wife called tell him about the gaffe.

Ben says that he was thrown off guard when numerous entertainment journalists inquired about his "wonder sperm" until he got home and Jennifer told him about her comments.

Watch Ben's entire interview tonight on The Tonight Show with Jay Leno at 11:35/10:35c on NBC.