Quick quiz: what's the one thing you don't want to bring up when interviewing Bill Clinton on TV?
Perjury? "Don't Ask Don't Tell"? Or, perhaps... semen? Yep, semen is just about the top of the list.
Pity then poor Ann Curry, presenter on NBC's morning television program Today over in America, who did just that, dropping the "S-bomb" while discussing Bill Clinton's top five holiday books... in front of Bill Clinton.
Speaking faster than you've ever seen anyone speak before, her recovery after the incident was frantic but successful, quickly correcting herself and asking her other guest, American Office star Mindy Kaling, a follow-up question.
What makes this cock-up so embarrassing for her is what she was trying to say in the first place: Seamus Heaney.
How do you get the name "Seamus Heaney" mixed up with "semen"? Did she think "Seamus" was pronounced "Seemus"? Oe perhaps that's the power of Bill Clinton... you just can't help but bring it up.