The One With The Tea Leaves - S8-E17
Mona: Ross! What are you doing?
Ross: Not touching myself, if that makes anyone less uncomfortable.
The One With The Nap Partners - S7-E6
Rachel: Hi! I just want to apologize. I'm really sorry I was a baby.
Phoebe: That's ridiculous Rachel, we were all babies once.
Answer: Usually by the seventh night of Hanukkah you don't know what to get the other person, and you will probably resort to getting the other person something insignificant. Chandler is basically saying that the pen is a stupid gift.