What is the main conflict in The Odd Couple by Neil Simon?

As the curtain rises on this smoke-filled room we see Murray, Roy, Speed, and Vinnie around the poker table. They are concerned about the unusual lateness of one of their regular poker players, Felix Ungar. Oscar enters from the kitchen with food for his buddies, the phone rings. It's Oscar's wife complaining about his overdue alimony payments. Two more phone calls, one from Murray's wife and another to Felix's wife, Frances, inform everyone that Felix is missing because earlier in the day his wife declared an end to their twelve-year marriage.