S9, E12: Rachel is irritated to learn that her handsome new workplace rival, Gavin (recurring guest star DERMOT MULRONEY), has been invited to her birthday party. Meanwhile, Ross struggles to keep lascivious Joey away from Emma's beautiful new nanny, Molly (MELISSA GEORGE - "Thieves"). Also, Phoebe coaxes her boyfriend, Mike (recurring guest star PAUL RUDD), into helping her care for a litter of baby rats that were born in her cabinet.