moon over (someone or something)

moon over (someone or something)

To pine or yearn for someone or something intensely, often causing one to become depressed or melancholic. You can't just sit here mooning over your ex-boyfriend. It's over—you need to get out there and live your life as a single guy! She's been mooning over traveling to Japan since she was in high school. He's been mooning over Cynthia all day—just look at that dopey grin on his face!
See also: moon, over