Squick: In "The One with Joey's Big Break":
: [to Ross]
So who would you rather sleep with, Monica
Ross: Dude, you are sick!
- And then add in that Ross actually did kiss Monica once, in a dark bedroom at a college party, where he thought it was Rachel "under a pile of clothes".
Ross: You were my first kiss with Rachel?!
Monica: You were my first kiss ever?!
- Don't forget this line from Chandler in "The One With Ross' Tan":
Chandler: "Dude, stop staring at my wife's legs! (beat) No, no. Stop staring at your sister's legs!"
- In one Thanksgiving episode, Monica considers dating Richard's son. The two actually do get to this point in the end, but by that point, the others have already been squicked out.
"Are you sure you wanna be in a situation where you can say, 'That's not the way your father did it?'"
- Danny and his sister.
- The childbirth video, especially for Chandler and Monica.
- There was a Running Gag of Monica saying intimate things to Chandler without realizing Ross's presence.
Monica: Take off those pants, Bing! *notices a Squicked-out Ross* Didn't notice you there, Gellar!
- Speaking of Ross, it wasn't just Monica for him. He also clearly had some feelings for his cousin, Cassie (played by Denise Richards), though this was definitely amplified by his lack of romantic life up to that point (not that revealing that helped things, as Ross quickly realized).
- The writers seemed to like the incest jokes. Chandler's offhand line about undressing his male cousin Glenn when he was younger was thankfully shhed by Monica before he could go into more detail.