Hes older. And its complicated

Ill try to keep it short. We met when i was 16, and he was 24. But we clicked

I just turned 18, and I know this guy for about 2 to 3 years. He's my mother's friends son. I met him at a party where my mom works. We instantly clicked, we got along really well I dont think I've ever connected with someone as much as him. Im use ti people liking my older sister better. But he said he prefers me.

We go out to the movies about once every other month. When we really want to see a movie. So 1 week ago, we went to see Bohemian Rhapsody and when he saw me he said "you look beautiful, its nice to have my jelly to my peanutbutter", (i turned sooo red, my heart was going to fall out of my chest) he already graduated from UCSD, right now he is 27. We play around with eachother. But i think since he met me before i was 18, he still sees me as a little girl. (I do look young).

Should i tell him my feelings? Or not? Is he to old for me? What do i do?

Pleasee help.