Mercutio is used as foil to Romeo. The word foil in drama means "a character or scene that is set up as a contrast to another so that each will stand out vividly." In what specific ways is Mercutio a foil to Romeo?

Mercutio is a colorful, sexually-minded fellow, who prefers transient lust over committed love, unlike Romeo who falls head over heels in love at the drop of a hat. However, as his speech continues, Mercutio portrays a level of intensity that Romeo lacks. Queen Mab is a rather vicious figure who forces sexuality upon women in a largely unpleasant and violent way. While he shares this story, Mercutio's tone becomes so passionate that Romeo must forcefully quieten him.