Portland Passback Share definition Flag It's where you freeze your poo, and put it up your mate's bum. Then he poos it back in to your hand. Hey mate, we're bro's, right? Lets do a Portland Passback! Portland Passback by SelfishSi June 10, 2018 0 0 Get merch Get the Portland Passback mug. Buy Now — $32.95 See more merch