crabs is a STD(sexually transmitted disease) basically its sort of like head Lice but they set up shop in your balls....not literally your balls but your pubic hair. they're highly contagious, so if you have sex with someone whos got them, they'll jump ship and invade your privates. you can also get them from sharing a towel with an infected person. it won't kill you or anything but you'll be scratching your balls A LOT!
whats so funny about it is, its not something you want to advertise having. it like me walking around with a shirt that says, "i got flesh melting bacteria, come to me please".
Lol... I think alot of Europeans don't know the meaning of it.
Thnx for explaining.