Is something going on with O.J.?

Joey is sharing his new level in bed expirience. Chandler:

- I didn't know you had another level.

Joey:

-I know. Neither did I!

Chandler picks up a newspaper:

- Is something going on with O.J.?

What was that? Is this "O.J" related to the topic guys were discussing? Or Chandler simply wants a change of a subject?

I'm your father. I am The Head!

Ross has found out that he needs to leave for China. But his son just got born. So he asks Monica to bring a picture of his to Ben and show it to him once in a while. Phoebe takes the picture and mocks Ross:

- Hi, Ben. I'm your father. I am The Head!

I sense that it should mean something.

Chad

Monica just have found out that the guy she slept with is under 21 y.o. She is all upset because of all the age difference:

- I'm like those women that you see with shiny guys named Chad.

Why "Chad"? Is it like typical name for guys who are younger then there woman-partner?

Pirates again

Phoebe is looking for an extra job in a news paper. She is asking guys if they can see her operating a drill press. They want to to know why she needs a new job. Phoebe:

-For short-term work. Till I get back my massage clients.

Chandler:

-Pirates again?

What was this "Pirates comment" in reference to? It is just a very first minutes of the episode, so I am sure all the clues are in that very scene. But I still don't get it.

Holden McGroin

Joey is thinking that his name isn't good for a stage. At audition in the theater Joey is asked to introduce himself. And here he shares a new-found version of his stage name:

-Holden McGroin.

And everyone laughs. Why? I tryed to find a person he borrowed this name from, but didn't succeed. Then by accident I found an answer. Look into comments.

Fifth dantist

Rachel is running into Ross's apt where everybody have already gathered for poker, with words:

- Hi. Guys, guess what?

Chandler trys to guess:

- The fifth dentist caved, and now they're all recommending Trident?

Trident is a gum. What is the story with a 5th dantist?

Ya-yas

Girls have lost a poker game to guys. They want to have a rematch. Ross jokes that he is just happy to use any extra cash. Rachel is trying to bug him about it:

- So you get your ya-yas by taking money from your friends.

Ross:

-Yeah.

Chandler comments:

- Yes, and I get my ya-yas from IKEA. You have to put them together yourself, but they cost less.

Obviously Rachel and Chandler are talking about different "yay-yas". But what are they in those cases? The official dictionary has no clue. The Urban one has too many definitions...