When you have them sign the prenup.

Unless you're dating a complete idiot, you shouldn't have to say anything.  It doesn't take a rocket scientist to see the signs of money.

I tolld my wife as so as I won the lottery when we were dating I was working several part time jobs and holding down a 40 hour job just to make ends meet when I started coming home at 5 or before dark she said what did you do winn the lottery I said yes here is the portfolio of all the investments and lets go get a safety deposit box. The win fall has not changed us we still work just not so much overtime.My advice to you if you do win DONT GO AND SPEND SAVE SAVE SAVE invest !

As the relationship gets more and more serious, more and more information should be disclosed.  However unless someone is consciously living well below their means, I suspect that the signficant other will have a clue, based on the type of conspicuous consumption that is observable, such as car, home/apt, vacations.  I agree that a good indicator for potential trouble is if the other person starts acting a little differently when more information is disclosed.  

iT IS WHEN YOU CAN OR FEEL YOU CAN TRUST THE SIGNFICANT OTHER. AS A WIDOW IT IS INTERESTING HOW FINANCES ARE THE NUMBER ONE TOPIC TO THE OPPOSTE SEX, NO MATTER WHAT AGE HE MAY BE,AND HOW YOUNG A MIDDLE AGE WOMASN CAN LOOK.

First off, if a women I'm dating is well off i can tell right away.  Most people in their 30's that have money were born with it. (Ie. got their education paid for, car, down payment for a house)   Most people that were born with it are easy to identify.  This is not an insult.  I can tell that they just don't have the same worries/pressures as the rest of us.  They often don't understand how drastically different it is starting out with no debt as compared to having student loans/ car loan/ credit cards and maybe medical bills past due.

 Most people date within their social status.  When people date below their social class they usually use their money to make up for some other short coming such as age/looks/personality.  They attract the person with their money/success.  

In the rare situation where you just happen to like someone below you're social class I think you should let them know where you are coming from soon as you realize that there is serious potential.  To surprise someone after engagement is ridicules.  

Very few people who have money can resist the urge to flaunt it. If the new love interest sees you driving a luxury car, wearing expensive clothes or participates in a date or two at an exclusive restaurant, they will smell the money behind it. Rule number 1, it's always a thrill for the less affluent to spend somebody else's money and it always causes resentment when somebody else is free and easy with your money. Take action that will control or prevent the conflict before things get serious.  

What the heck does  DH stand for?

I'm revolted by some of the attitudes people have displayed about not telling the truth about finances to the person they are supposed to love.  You are not ready to enter into marriage with someone if you haven't been fully forthcoming about both parties' finances, be it wealth or debt.  It's no wonder the divorce rate is around 50% if people refuse to talk about it until it's time to sign your first joint tax return!  The time to have the conversation is not when you're about to walk down the aisle and you're already tense about wedding spending.  It's well BEFORE you even get engaged.  You should know exactly what you are getting into if you are making an informed decision about your compatibility with another human being.  How you deal with finances is as important as the compatibility of religion, family values and general morals if you hope to stay together long term.  And if you're worried he/she is only with you for the money, then get a pre-nup.  It still doesn't justify LYING about how much money you do or don't have.  And believe me, lying by omission is still lying!  

It for me is like you would want to say that you should not discuss money, until the money becomes one when you get married because whether you are rich or poor should not make a difference if someone loves you or not.  BUT if you are weathly and have assests to protect, and do not want to loose half Heather Mills style or future Myria Carrey, I also think that just prior to wedding pre-nup is a very good idea either man or woman.  Final comment is again man or women is maybe more that a person make how much debt do they have, getting married and then finding out not as much that a person only make $20, 000 a year but that that perons for some reason also has debt of a quarter million or more.