Something I did not realize until it was explained to me by a medical authority --
When you jizz inside a woman, as I do as often as possible, those little swimmers look for an egg to fertilize. If there is no egg, they keep swimming. For the rest of their life. Up thru the vagina, into the cervix, and up the fallopian tubes. And as we all know, the fallopian tubes are open near the ovaries, where their job is to capture the egg released by the ovaries and guide it down into the cervix. But there is no one-way valve there. My little swimmers just swim right on out into the abdominal cavity. And just swim around and around in there. Looking for anything they can burrow into and impregnate. Basically anything below the diaphragm in the abdomen is fair game.
And this my friends is the argument I give to my wife to convince her to give me a BJ.
