Dating a younger guy!

I really like this guy but he is 10 months younger then me and in the grade below me. I'm a junior and he's a sophomore. When I first met him over the summer we became really close friends but now we are both starting to have feelings! He is so much taller then me and acts older so I don't think it's that big of a deal. When he turns 17 then I will turn 18. I'm just worried that people will say things since the guy should be older.