There’s a black guy in my school that he slapped my ass while we play football. And since that day I feel horny and want him to fuck me so hard and become his slut. Any advice to seduce him to fuck my ass ?

So, the first thing you should know is that, over time,
people’s sexuality does change.  Its almost
inevitable.  People change, tastes
change, desires change.  The problem with
your particular issue is that someone (you, in this case) cannot bring about
those changes out of the blue.  If he’s
not actually in to feminine guys or trans women, there’s not going to be a whole lot you can
do to bring him around.

But, if you’ve just got to have him, you should first figure
out if he’s actually into someone like you.  He might
have just been slapping your butt because that’s what guys do in sports (or so
I’ve been told…).  Try casually
bringing up homosexuality or transgenderism in conversation, and keep what you say neutral.  If he reacts with disgust, maybe it’s time to
look for a partner elsewhere.  Even if he
is one of the (possibly) mythical “closet cases”, you’re going to
have a hard time convincing him to give you a go.  If he reacts more positively, or even
negatively towards those who are negative, well… maybe you have
a shot.  Keep directing bits of random
conversation (at different times, not all at once) towards what kind of guy or
girl he wants.  Then, the annoying part,
become that guy or girl.  If he likes
muscular men, hit the gym.  If he likes
preppy girls, start studying fashion and makeup.  You can’t change him, at least not without a
really long term game plan, but you can change yourself.  Most people will tell you that if he won’t
accept you for who you are, he’s not worth it.
But, the fact is that any relationship, even if it’s just a sexual one
like you’re talking about, is going to be about compromise if it’s going to
work. You’ve always got to give to get.  And
if that’s a road you’re willing to travel, it’s time for you to get to it.

Once you’ve become his dream girl (or guy), then you make
your move.  And that’s going to have to
be up to you, and your judgment of what kind of moves he likes.  If he’s willing to do something
non-traditional in a relationship, and you’re exactly what he’s looking for,
and you’re obviously interested him, you’ve done about all you can.  The rest is up to fate/luck/destiny/random
chance and him.

Now, go get your man!  And best of luck to you!