This is what you call someones butthole after they had a fun filled night of anal sex and their butthole is twice the size it shoud be.
"My boyfriend fucked me in the ass so hard last night and now I have a Swollen Starfish.''

"Dude I nailed my girl in the ass so hard last night! She has a Swollen Starfish!"
by SiloJohnson72 December 13, 2011
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