when Chandler was tied up in the office with Rachel's boss Joanna, he did a deal with Rachel along the lines of telling all the girls that he's got a big one (so that he remained tied up or something). Rachel said this to the girls over coffee and Joey said "no he doesn't"
Later in in the series when Chandler got together with Monica, she said to him "you know what your nickname is Big Boy"
so what's the real story?