Season 9: Episode 215: The One in Barbados (Part I)
The gang (including Phoebe's boyfriend, David) travel to Barbados for Ross and Charlie's conference. The humidity makes Monica's hair bushy and wild. The constant rain prevents most of the gang from enjoying their time on the island. David is worried he can't compare to Mike; Chandler tells him Mike's failing was that he was against marriage, so David decides to propose to Phoebe. Monica, knowing Phoebe is still hung up on Mike, tries to undo Chandler's meddling with some of her own, and calls Mike asking him to step up. Chandler accidentally erases Ross's keynote speech, so Ross and Charlie stay up all night together to rebuild it, while Rachel and Joey have fun crashing the neighboring pharmaceutical convention. Ross and Charlie learn that they have a lot of fun together, and a lot in common -- including ex-es who turned out to be gay. Rachel is about to tell Joey how she feels about him, but they're interrupted. David begins to propose to Phoebe, but Mike shows up and proposes first. Phoebe says no, but gets back together with him, knowing that now they can have a future together.