"Nora...Mrs. Mom...Your...Bing" - he's stumbling over words. Chandler's mother's name is Nora Bing. If you are a child, you would refer to your friends' mothers as "Mrs. Bing." When you are an adult, you would probably refer to your friends' mothers by their first names ("Nora"). At this point in the series - Ross & Chandler are in a transitory period where you go from one to the other. It's a bit awkward trying to figure out which name to call them. Also, the situation is really awkward because you generally don't kiss your friends' moms (or dads). So Ross is trying to figure out how to refer to the woman and just throwing out names... "Nora" "Mrs. Bing" "Your Mom" and mixing them up in an attempt to make the situation better. "Knowledge is a tricky thing" - That sentence is a tricky thing. * Some people think that if Joey knew, he should tell Chandler. * Some people think that if Joey knew, he should keep it a secret from Chandler. Either way could be a problem. Joey can't say "I didn't know," because that would be a lie. He also can't say "I knew," because that would make Chandler mad. So instead he's saying that it's hard to tell whether or not he knew.

Apparently her name is Mrs Bing. I think maybe he was just fumbling his words, and they came out wrong. 'Knowledge is a tricky thing" - just means that knowing something can be complicated. Because he knew, it made the situation complicated, in terms of whether he should or should not say something.

Gary, Its a caption. but i think its right.

What makes you think it is 'Bing'? Can you give a reference? Is that what you heard, or is it a caption?