That's "Younger Girl," a cover of a Lovin' Spoonful song, written by John Sebastian. That was the first we heard from The Critters in 1966 — my all-time favorite music year, half a century ago. (Compare the Spoonful version, here. And compare "Prison Wall Blues," which some people say is the source of "Younger Girl.")
Ciccone wrote the follow-up single — also from 1966 — which lacks that spritely joy of the Spoonful song, "Mr. Dieingly Sad":
Ciccone was 70.
ADDED: "Younger Girl" gives present-day listeners the impression that the man is singing about underage sex, though it gets no more lascivious than this:
And should I hang around,
Acting like her brother?
In a few more years,
They'd call us right for each other.
And why? If I wait I'll just die.