Rachel is very jealous to find out that she missed Emma's first laugh, and is not amused to find that Ross was singing a song about "a guy who likes to have sex with women with giant asses" to their baby daughter, even though Ross tries to point out that the song "promotes a healthy...body image."
At the end of the episode, Ross and Rachel sing a duet of the song and even do some dancing along with it, realizing too late that the rest of the group is watching them do it.
Phoebe also begins speaking in an elite Katharine Hepburn-style accent in an effort to fit in with Mike's rich parents.
Mike encourages her to just be herself, but that produces disastrous results as Phoebe provides details about her life on the street (including the fact that a pimp once spat in her mouth), playfully punches Mr. Hannigan in the chest (unaware that he just had surgery), and provides Mrs. Hannigan with far too much information about Mike's sexual behavior.
When Joey asks Monica and Chandler how he should invest his money (as opposed to his current system of taping it to the back of his toilet tank), Monica suggests investing in real estate and even tells Joey that her old boyfriend, Richard Burke, is moving out of his apartment.