The “you’re my lobster” phrase comes from the Season 2 episode “The One With The Prom Video.” While Ross tries to get back together with Rachel following a fight, Rachel doesn’t believe they will ever work as a couple. Phoebe, on the other hand, believes that the two are lobsters and explains her theory to her friends, even saying, “You can actually see old lobster couples walking around their tank, holding claws.” When Rachel later sees the prom video and finds out that Ross was going to take her when her date supposedly stood her up, she is overwhelmed with emotion and kisses him. Phoebe happily exclaims, “See, he’s her lobster!” Ironically, Ross is allergic lobsters, making this comparison pretty funny. 

Unfortunately, knowing that lobsters don’t, in fact, mate for life might make this scene less romantic for some. It would’ve been more fitting if Phoebe equated them to wolves or beavers, animals who do share that beautiful and eternal bond. However, they probably wouldn’t have as nice a ring to it, and we can’t really imagine someone saying “you’re my wolf” or “you’re my beaver.” Even though Phoebe’s claims aren’t based in truth, this moment between Ross and Rachel definitely still hits all the feels to this day.