Tunnel Twins Share definition Flag 1-When two girls hook up with the same guy; not necessarily at the same time. 2-Girl version of the "Eskimo Brothers" "OMG!! Did you fuck John last night?! NO WAY, I fucked him last week! We're tunnel twins!!!" Tunnel Twins by .McCoy. September 5, 2013 0 0 Get merch Get the Tunnel Twins mug. Buy Now — $32.95 See more merch