When two girls, (lesbians) "Double End" a potato, meaning each party takes one end of the same potato and pleasure themselves by humping each other.
"Jenna and I went potato surfing while Brad and Joey watched, it was the most wonderful experience of my life!"
"I watched a couple of girls Potato Surf in my basement, it was great."
Potato surfing was originated on Prince Edward Island on Canada's east coast. During the potato harvest in the 1940's , most of the eligible men were away at war so the women were left to work the potato fields. On the weekends they would head to the beach for some fun and started taking the surf boards with them. Naturally potatoes were abundant so after surfing they would pleasure themselves with a potato and there the term was coined " potato surfing".
She was potato surfing for so long and so hard her fine china needed a real good scrubbing.