My girlfriend and I were having a conversation the other day about sexual euphemisms and I told her about the following I'd seen on Saturday Night Live's Weekend Update by Tina Fey
According to a report released Tuesday, female inmates in the United States have been victims of sexual misconduct by corrections employees in every state, except Minnesota. So ladies, if you wanna rob a bank, but you don't want your cooter poked, head to beautiful Minnesota, land of 10,000 lakes.
It can't be that old, Ben Jones on Dukes of Hazzard played a character named Cooter and nobody thought anything of it. I've heard it used in this context many times since I saw that.
I checked etymonline and it only talks about turtles and a vague reference to an obsolete use of the word coot. Clearly, that is not from where the connection came since its use as I've described is recent.