This account by Bennett Cerf (see above downloadable PDF file) appeared in the January 1966 issue of Playboy. Cerf states therein that he was at the luncheon meeting at the Ritz Hotel in New York on March 19, 1926 when Theodore Dreiser threw a cup of lukewarm coffee into publisher Horace Liverights’s face.
Cerf’s account is problematic.
In his biography, Firebrand: The Life of Horace Liveright, Tom Dardis observes:
The account of Bennett Cerf in his memoirs [At Random: The Reminiscences of Bennett Cerf, not the account posted here] has no firsthand information, for Cerf was not present at the event and had left B&L [Boni & Liveright] a year before it happened. (pg. 200)
Cerf says that the only persons at the luncheon were Dreiser, Horace Liveright, and himself. He does not mention film producer Jesse L. Lasky, who was also there to discuss the sale of film rights to An American Tragedy.
— Roger W. Smith