Phoebe Buffay's theory that lobsters link claws and mate for life.
The person you are supposed to be with the rest of your life.
Phoebe: (in reference to Ross and Rachel) hang in there, it's gonna happen
Ross: Okay, now how do you know that?
Phoebe: Because she's your lobster.. come on your guys, it's a known fact that lobsters fall in love and mate for life. ... you can actually see old lobster couples walking around their tank holding claws