You're So Juvenile Latley

The story:

I was 22 and I was in the car with my boyfriend of the Summer. We were heading to Lake Geneva to go swimming. During the long car ride, he got out his CD collection and told me I could pick out any CD and listen to it. I was looking at the Def Leppard CD, and he said I bet you love the song "Pour Some Sugar On Me". I told him that I don't know the song. He said I would if I heard it. He put it in, and I started singing along..."You're So Juvenile Latley..." He looked at me really weird, and asked as he was laughing really hard...What the hell are you singing? Then I realized that the lyrics in the title of the song were the lyrics I was singing incorrectly in the song.