Simply means Anal sex. It is derived from the fact that Spartan men were forced to bond using anal sex and anal sex is often used as a birth control in modern society.
"Dude, you gunna need a condom tonight?"
"Nah, I'm just gunna stick to good old Spartan birth control."
"Nah, I'm just gunna stick to good old Spartan birth control."
by kevin03246 November 19, 2008
by Kevin03246 December 12, 2007