Sitting in a Tree

Okay, so, this joke is incomplete. It relies on you knowing the rest of the rhyme, which goes like this: "K-I-S-S-I-N-G. First comes love, then comes marriage, then comes the baby in the baby carriage!" It's supposed to be funny 'cause it's a childish rhyme about love and marriage. And let's be honest, you probably still believe in that fairy tale. You are so basic!