Madonna has had a few high-profile love interests in her time. She recently admitted Tupac Shakur was one of them! The rapper, in fact, sent an emotional letter to her from prison, including an ominous warning: "Please be careful Madonna. Everyone is not as honorable as they seem. There are those whose hearts bleed with envy and evil. They would not hesitate to do you harm. Let my 5 bullets be proof of that!”