How about not telling a lady you're a broke daytrader? http://video.foxnews.com/v/3559690166001/what-not-to-say-to-women/?intcmp=obnetwork#sp=show-clips
Don't tell her you plan on making $500 a week on a $2000 futures account. http://elitetrader.com/vb/showthread.php?t=284078
Don't tell her the secret to your trading is buying the 20 day breakout with a 10 day stop that risks 2% of your capital.
Don't tell her you took the Williams million dollar challenge. Don't tell her you graduated from the TWMPMM school of trading. Don't tell her you're a disciple of WD Gann. Don't tell her you have an autographed copy of Robert Prechter's Conquer the Crash. Don't tell her you have a Series 3 license, and you can be her futures broker. Don't tell her you're a full-time, professional E-mini S&P scalper.