when about to have sex with a woman on her period, you pull out the tainted tampon that was in her vaginal canal
Guy 1: "hey man, did you guys get it on last night? I was chatting with her girlfriend and she said there was no chance cuz she was on her period. So we were kind of laughing at you for trying so hard."
Perp/Guy2: "Dude, you underestimate me; she was a little cranky, but once I pulled the ripcord it was all good"
Hence: Pulling the rip cord
Lots of couples enjoy sex on a regular basis, regaurdless of the time of month for the female. Pulling the rip cord is common practice for some.......