When the men and women from come together into a giant line, plant themselves on a road and then they all spread open their asscheeks far and wide forming a massive mile-long cheek-opened line of people in form of protest.
A hypothetical club whose members have had sex with enough men that a line of penises of said men were arranged from end to end would stretch a mile. If the average human male penis is 6" this would account for, on average, 10,560 men. If a candidate were to include beasts of burden into their calculations the mile could be reached much faster.
My sister-in-law, despite getting a late start in life, is just slutty enough to be well on her way to becoming a member of the mile long club.