Guatemalan sinkhole
When a part of the rectum protrudes from the anus due to massive amounts of anal sex.
Holy crap, dude, I flooded her ass with so much jizz last night that it collapsed. Yeah, it's a real Guatemalan sinkhole down there now.
Guatemalan Sinkhole
An asshole that has been double penetrated so many times that it begins to resemble that giant sinkhole in Guatemala.
Jenna Haze has been DP'ed so many times that she's turned her ass into a Guatemalan Sinkhole.