when i was in 8th grade a girl in my grade dated a senior. i thought it was weird then. and everyone called him a pedo but nobody did anything about it.
I still go by 18 even if im in one of those weird "hey its 16 here!" states. i think 18 is a good guideline. And even then an 18 year old would have to really pursue me tenaciously and convince me theyre okay.