Yes, my 5 year old has autism, along with apraxia (severe language impediment). He presents a new challenge every day!!!!
Yes, auti's are quite bright, its a matter of finding the avenue their brains want to take. Actually, 80% Nobel Peace Prize winners & alot of the greatest inventors (Einstein, Edison) all had forms of autism - Aspergers (high functioning).
It can be extremely difficult, but extremely rewarding as well. I would "assume" that Sean has a difficult time with social situations and picking up clues as to others true emotions. Hopefully, this helped defray some of the negativity that would come from knowing your own father would turn you out because of a piece of @$$.
Good luck to you
Peace,
Rhonda