''I am by nature shy and uncommunicative,'' says writer John North, the protagonist of this less than satisfying novel by Begley (''About Schmidt''). Still, North confesses all -- specifically, all about his adulterous relationship with a female French journalist -- to a nameless stranger at the ominously named tavern L'Entre Deux Mondes (Between Two Worlds). Despite his explicit accounts of multiple trysts, North emerges as a flawed but self-aware man with a deep love for his wife and an abiding concern for his invalid parents. All cheating husbands should be so worthy of sympathy. Too bad the other characters, particularly the women, aren't nearly as well drawn. North may be shipwrecked, but Begley's left the ladies at sea.