Two adult siblings are heatedly discussing their respective fertility. The 31 year-old sister says to her 28 year-old brother:

You know, men have it so much easier than women. After all, men produce sperm every single day from the time of puberty until they die.

Women, on the other hand, are only fertile the few days around the time they release an egg just once a cycle, and they are only fertile from puberty through menopause.

Just at that moment, their grandmother on their mom’s side chimes in from the kitchen “All that may be true, but one thing you both share is the fact that I carried each one of you in my own belly.”

HUH? How is that even possible?

(Answer on Friday).