Wikipedia has a more prosaic explanation of the song's subject:
"It is sung from the point of view of a man who is frustrated that the woman he loves will not agree to have sex with him. He coerces her, pledging to "shower [her] heart with tenderness" if she submits, but also issues an ultimatum ("It's now or never") if she does not."
The lady appears to be the one with the willpower, at least sufficient to rebuff the advances of the man. It's all a bit iffy really, albeit not as iffy as
Young Girl.