so we discussed this as we were watching the friend's finale, but as alinna and i were watching one of the syndicated episodes, the topic was brought up again. has every friend kissed every other friend? we were trying to come up with examples for each one, but we came up short. anyone can help? this is what i can do so far:

1. rachel and monica: kissed to get their old apartment back from joey & chandler
2. rachel and phoebe: phoebe kissed rachel to see what all the hype was about (on the episode that winona ryder was on)
3. rachel and joey: well, they kissed several times when they had crushes on each other
4. rachel and chandler: on one of the episodes where chandler and monica were still secretly dating, chandler got up to leave the apt and kissed monica on the lips before realizing everyone else was still there. to cover up his mistake, he proceeded to kiss rachel and phoebe on the lips as he said goodbye.
5. rachel and ross: too many to even begin
6. monica and phoebe: drawing a blank... anyone?
7. monica and chandler: when did they not kiss?
7. monica and joey: ? drawing a blank as well. did they kiss on that flashback episode when monica first met joey and he stripped? i don't think they did.
9. monica and ross: ross kissed monica in a flashback episode when monica was in a dark room and ross entered it and kissed her on the bed thinking she was someone else.
10. phoebe and chandler: see number 4 above. also kissed when phoebe and rachel knew that monica and chandler knew that they knew that monica and chandler knew that they were dating (did i get that right?) albeit, it was a very ugly, unwanted kiss, but it was a kiss on the lips nevertheless.
11. phoebe and joey: joey kissed phoebe because she wanted to have the perfect kiss (? perfect kiss? i forgot what the criteria was) before she turned 30.
12. phoebe and ross: drawing another blank *edit* thanks to g. ma - ross and phoebe did kiss in a flashback episode - all i remember is they were playing pool, and then when they tried to clear the balls on the table, the balls just ended up rolling everywhere.
13. ross and chandler: ? i swore i had an example for this, but now my mind has drawn a blank
14. ross and joey: ross kissed joey to help him audition for a gay part. unfortunately, ross kissed joey after the audition.
15. chandler and joey: joey kissed chandler during one new years party when originally every friend had a date or plans, but by the time midnight rolled around, everyone was miserable and dateless. as the clock struck 12, chandler starting yelling, "somebody kiss me! somebody kiss me!" and much to his surprise, it was joey who did.

so that's all i could come up with. this is definitely testing my friend's knowledge. anyone can help with the rest? i'm sure someone out there watches friends more than i do!