The One With Ross' Inappropriate Song

S9 E7: When Chandler's former romantic rival intends to sell his apartment, insecure Chandler persuades Joey to help him secretly inspect it. The guys are aghast to discover an old videotape that might feature Monica having sex with her ex-boyfriend. Meanwhile, Ross accidentally discovers that singing the suggestive lyrics to "Baby Got Back" is the only way to get baby Emma to laugh, but he fears telling Rachel about the trick. And Phoebe fails to impress the uptight parents of her boyfriend, Mike.