I'm a bit like that so I might not give useful information.
Coming on here asking for guys to suggest what you can say, it might help in the beginning, but if you can't keep up a certain persona (and you can't keep asking for help with what to say) then he won't know the real you.
So my advice is to embrace your own ways and just go with it - because what God gave you can't be wrong
But if you do want a tip on "seducing" him your first task is to get to know him. You could try the following:
1. Make eye contact the next time you see him. (Forget about smiling - eyecontact is all you need). This will get him to notice you. Don't say anything at first.
2. You can play eye flirting for a while, and after having seen him a few times you could go near him (and you do not need to smile - don't worry about smiling at all as you're expected to be nervous like most people doing this). Sit or stand next to him. And say something friendly - eg - an open-ended question
. Open-ended questions give the other person a chance to speak more. Examples of these could be: "What do you think of this place?"; "Have you heard about x in the news/sports?"; even just "Hey how's it going?". ***Tip*** Standing or sitting side-by-side is far better than standing or sitting face-to-face. The other person feels that you are more "with" them (on their side, with their interests at heart) when you're sideways to them. Sideways at a slight angle sounds good. Face to face is a more aggressive stance. (oh, I learned that from a book).
From there you can talk a bit more. Only smile if it's natural to you. But it's reassuring to see a smile from the person you're talking to, so if it comes to you, let it show. Finally, if he has shown interest in you and you feel worried about being perceived badly, then after some time talking you could let him know you've mild aspergers and think literally. Then he'll realise and cut you any slack for misunderstandings. But don't labour the fact on and on - just explain quickly and move on to another subject. Like being gay, it's only a single aspect of you. Also don't introduce yourself as having Aspergers in your opening line, spend some time talking generally and then if you think it's appropriate (to come out as Aspergic) to the conversation bring it up.
3. Give him some time to decide if he likes you or not, don't come on too strong, and you will obtain one of two results. He will be interested or not. If he is not interested let him go. We all experience rejection. Just tell yourself it's a shame he missed out on you.
Remember that there are no rules to any of this - you can do what you want - try not to worry about not knowing how to go about it - sometimes it's best to go ahead even if you're not sure something's going to be perceived well. If you have only good intentions for everyone and yourself, then you will be OK.
***To keep conversations going, you need to tell yourself that it's all about him. Pay good attention to what he says, and ask anything about what he's saying that you find interesting/strange/perplexing/exciting. After a while he will want to know more about you but you can score good points by making it all about him to begin with, saying only very little about yourself.***