A natural internal navigational device that allows you, no matter how drunk or unappealing to somehow come across a lady with standards so low that she may ensure your night out on the pull was not in vain.
I was a steaming wreck, sometimes I wonder how that twatnav works. She was a total minger but I guess I must have had fun at the time!
"Jo had an enormous twatcave"
"your twatcave is almost as big as your mum's vaginal trench"
"i heard she once fit a whole shopping trolley dog up her twatcave"