Until You Came

Mercury, a planet with no moons to keep it company, a planet closer to the Sun than any other, and a planet that can never approach the Sun because of its Roche limit. Mercury wants to know where it stands in the Sun's heart. But so many planets orbit the Sun that it can't tell whether it is the Sun's favorite. Traveling around is dull, but at least I can keep you company. ???

Theme: I love you, so we're together.