Purity Rings Have An Expiration Date On “RHOA”

I wanted to be excited that Kim Zolciak’s 13-year-old daughter Brielle actually asked her mom for a purity ring on the latest episode of “The Real Housewives of Atlanta,” but the whole thing fell apart for me when she started negotiating her abstinence expiration date. 18? 19? 20? I don’t know a whole lot about abstinence rings (or abstinence), but I was under the impression that wearing one meant you were saving yourself for marriage, not for college. So just to recap, Brielle got a $3,000 diamond ring to keep her hymen intact until college. And Kim thinks this is brilliant. Am I missing something here? Do purity rings expire whenever you want them to? And … what the hell is Kim wearing? Please help me understand.