Valentine's Day is just around the corner ... and who better to give advice on how to have a romantic evening than Nelly and Ashanti ! We caught up with the music power couple on the red carpet of the Fanatics Super Bowl party Sunday in San Francisco, California. When our photog asked ... "What's the secret to a Valentine's for you two?" even he didn't think they'd give such a candid answer. Nelly gave us a knowing stare ... while Ashanti blurted, "The bedroom!" The "Hot in Herre" rapper