Think twice about accepting a purity ring. Sure, it may be gold-plated, but you're signing up for years of sweaty dreams about Nick Jonas and nagging, dirty thoughts about the removable shower head.
If your Dad was the one who offered it to you, it means he's thought about you in a sexual way, probably because of your new boobs. It's a good idea to start locking your bedroom door, especially when mom's at book club.