Get to know him before you date him.
There are things called friendships.
Use your head. And if you're going to consider it, being that you are older, you'll be expected to do so.
Bisexuality is a big issue, though. If he truly is, rather than just an undecided emo teenage boy, he's going to flip-flop at such an age of... exploration.
I still say it's a bad idea, but you'll do what you want.
A work of art is an invitation to love.