look up any word, like fleek:
 
2.
When someone posts images that aren't them on a dating site or app (see cat-fishing), but you still fly across the country to meet them, you end up sleeping with them, and get crabs.
"So I met this hot girl on Tinder, she sent me shots of herself in a bikini, we made plans for me to fly to Chicago to meet her, and then I got crabs. Textbook crabshacking."

"I couldn't help myself. He was so cute and sent me hipsterporn. I had to crabshack that fool."
by McFuckersons November 23, 2013
 
1.
Storing several loads of semen inside your vagina, until it begins to smell like the ocean or seaside, then trying to put that vagina on someone's face.
Man: What smells like a fish market?
Woman: I'm Crabshacking you when we get home!
by Tostig_the_Bastard September 02, 2014