Puppy love (used as a noun)

First Example:
            Tom: Chris said your son is dating?
            Carol: That's what he's telling everyone.
            Tom: I thought he was only 13!
            Carol: He is. It's only puppy love. But he and his girlfriend are so cute together.
            Tom: I remember my first girlfriend. We were both 12, and her name was... actually, I don't remember her name.
            Carol: Don't tell my son that. He told me he's going to marry this girl one day.

Meaning: The expression "puppy love" refers to the strong feelings at the beginning of a relationship, often used for young people and implying that the relationship won't last. Here, Carol says that her 13-year-old son's relationship is only "puppy love," which Tom seems to agree with when he can't remember the name of his girlfriend when he was 12.



Second Example:
            Sheila met her husband in high school; they were both only 17. Their parents and friends said it was just puppy love, and that they'd never last. But they got married 3 years later, and they have been happily married for 20 years now.

Meaning: The expression "puppy love" is also often used in this context, referring to relationships that started at a young age but developed into something long term.