How do i tell if he's gay without asking?

i think that i am gay now and i accept it(ill be 14 in two weeks) and theres this boy that i fantasize about all the time and can't get it off of my mind. durin class we tickled each other once and he showed me his thighs that im ashamed to admit i liked. no one even suspects that i am gay right now and i don't want to come out just yet but if he is gay (he's never been in a relationshiop boy or girl) then i want to go out with him just in secret. but how do i find out if i straight up tell him bout me and my fantasizes he mite get weirded out or tell people . how do i solve this(i would prefer other gay people who have been in this situation before and had it work out fine for them but anyone is fine i guess)