The Material Girl helped one fan with a proposal of a lifetime at her July 8 concert in Amsterdam.
"Who are you going to ask to marry you?" Madonna asked the woman. "Well, do you want to ask him to marry you in front of several hundred thousands of people?"
Madonna handed the mic over to the excited woman -- after warning her to not "slobber all over my microphone" -- who then asked her boyfriend to marry her. He said "yes," and a wave of cheers erupted from the crowd.
After taking her mic back, Madonna cheered the couple on, chanting, "Tongues! Tongues! Kiss with tongues!" as they kissed for all to see on the jumbotron.
"I'll give you once piece of advice. Never go to bed angry," Madonna told the couple before she got back to the music.
Madonna's advice is sound, but other celebrities aren't so sage when it comes to marital wisdom. Click through the slideshow to see stars whose advice on marriage shouldn't be taken.