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A thong berry is what happens when you think you're done with your period, so you put on a thong, but you end up with a congealed blob of gooey uterine blood stuck on your skank floss.
I thought I was done leaking uterus jelly, so I wore and thong that day and ended up with a stank thong berry.

I like CapnCrunch with thong berries
by 2LBSofTOE March 03, 2014