Musical Mondays #15 - Confusing Chorus

I recently attended an event at which the song "Single Ladies" by Beyonce was played. (By played, I mean blasted from speakers at a volume that could potentially lead to the phenomenon of eardrum combustion.)
I was very confused by the lyrics in the chorus.

Here's the chorus:
Cause if you liked it then you should have put a ring on it
If you liked it then you should've put a ring on it
Don't be mad once you see that he want it
If you liked it then you should've put a ring on it

What exactly is this "it"? This pronoun lacks a clear antecedent. I would assume from the context of the song that the "it" is the woman. But one does not really put rings on women, and women are female and should be referred using feminine pronouns...One does, however, put rings on fingers! Ah-ha! But it is not common for people to go around admiring fingers.
Does "it" refer to the woman or the finger? Does the first "it" refer to the woman and the second to a finger? Is it saying that if you like a finger you should put a ring on the finger? Is it saying if you like a woman you should put a ring "on" it/her? Is it saying if you like a woman's finger you should put a ring on the woman? What? What? What?