I think that, what intimite relationships are concerned, financial discussions are the most basic ones to avoid. It's very difficult to live with someone and make up a household budget, especially when both incomes differ (or one of them has no income). If this is hard enough, sharing these problems with your children is even tougher.
I think this goes for every intimate relationship wherein partners do not have sufficient funds to do everything they please.
Born but to die, and reas'ning but to err.