3x12 "The One with All the Jealousy"

Ross is jealous of Mark, thinking he is trying to steal Rachel away causing him to shower Rachel with romantic gifts at her workplace. Joey's numerous lies on his resume catch up to him, as he is forced to teach a very hard dance to an entire Broadway cast. Monica dates Julio, a busboy from the diner who writes a poem for her called 'The Empty Vase'. Touched, Monica sleeps with him but is then told by Phoebe that the poem is referring to her