SPF 69 is a term used to describe the climax of sexual intercourse when the man (doing his woman doggy-style) removes his penis from the vagina and skeets on her back, and proceeds to rub it in... like sunscreen.
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!