O wtf dude, shes young!?

K i just recently turned 17. My friend introduced me to this banging girl at a party, i mean she looked soooooo good. We talked, and i guess i said the right things because she gave me her number before I left. Then i ended up cruising with some friends and the same friend said we should go hang with her and her friends so we did. Again me and this girl talked and whatever and it was kool. Then she called me and said we should meet alone and I was stoked. After that night I told a friend about her and he was like "word, that girls in like 8th grade right now." I doubted it so I asked around and sure enough this girl is in 8th grade. Now she wants to hang out again but i don't think i should, she just finished 8th grade and is going 9th, and I'm going into 12th. Is that to weird or what? shes crazy fun to be around and she seems way older than she is. Should i call it off our not? The thing is even though i now what grade she is in, i still don't know her age.