In The One with All the Resolutions (1999) Ross stated that his New Years resolution was to have just one divorce 1999. In this episode Ross and Rachel file for divorce meaning he broke his resolution.
Chandler agrees to babysit three "puppies" (which end up being Frank and Alice's triplets). Later in "The One Where Chandler Doesn't Like Dogs" we learn that Chandler can't stand dogs and would not even begrudgingly agree to puppy sit.
Despite the mispronunciation in "the one with all the Thanksgivings", Joey is right-- it's pronounced as "Por-shuh". Many people think the "E" is silent but you do pronounce both syllables.
When Monica, Chandler, and Phoebe are changing the triplets, Chandler holds up one of the babies who is supposed to be a girl. The angle is such that you can clearly see the baby is in fact a boy.