Why not suggest to start off as friends? Is less of a big step in his mind.
I am actually like that as I have only really ever had two girlfriends due to autism.
The first issues are faceblindness when I went to go on a date when in collage at age 16, and I did not know until the next day that I had been standing a few feet away from her waiting at the college gates for her and I did not realize it was her. After half an hour of waiting I suddenly realized that there were five sets of gates around the college, so in a rush, I jumped on my bicycle to check the others. When I rushed back to the main gates I saw the lady walk down the hill. I did not realize it was her!
I waited another fifteen minutes and assumed that she wasn't going to turn up so I went home.
The next day her friend told me off in a really nasty way in how I had upset her feelings. The rest of the two years in college they avoided me and not wanting to be theperson to upset them, I hid away and avoided them.
But I was so upset that I refused to date anyone else until I was 36 and this lady who I worked with convinced me it would be ok for me to date her and she said she would approach me so I would not mess it up!
I dated her for around six months and was going to marry her but she suddenly ended it with no warning or explination. Just cut off all contact and her whole family refused to speak to me. I became suicidal blaming myself and Divine intervention saved me on more than one occasion... (Turns out she had been dating others the same time).
Anyway... I could not date for ages after that! I tried about three ladies just for an hours walk on tbe beach one occasion at a time (As I very bravely kinda learned how to ask out somehow? Not sure how as I have not remembered how I did it), but I didn't have the heart to go on a second date with any of them after that walk on the beach as the shock and happenings of the first GF were on my mind... And this was at least a year or two later... I think at the time I wanted to prove to myself I could ask ladies out?
But I had also been hurt by asking ladies out in the past and I was very polite, but was met by the cruelest of answers that not even the vilest of men would have said and I am not even joking!
So that was thre point when I stopped asking women out after having asked around 20 out in my lifetime.
Fast forward a decade after the last date so I was well into my mid 40's (Around six years ago?. Maybe seven?) and I found myself dating a lovely exceptionally kind hearted lady who was on the spectrum as was her son. Again, she asked me out, but it was done online. It was mostly via the phone or via online though she came down from Yorkshire on her holidays twice a year. It eventually ended when I hesitated, as she was forever asking "Do you love me" and I once while on the phone hesitated for a brief second and that was that! (Though I had been praying that if she was not the "Right one" that the Lord would do something to separate us... I really loved her but somehow could not work out if I loved her as a close friend or more? It was harder with her as she was "Non-touch" so I think I only kissed and cuddled her once or twice the entire time we had dated which was spread over a year and a half? (99.6% distance dating).
Anyway! Since around six to seven years ago when that ended, as I really found it hard to not have feelings for her, I felt I actually found her a man that I knew was a nice gentleman as we talked many times online. I heard that they got married. I was so happy for them!
But I had been texting her after it was over as I was so used to chatting to her, and she wanted me to stop texting so I deleted all contact details I had outnof respect for her (She had already dissapeared from the sites I was on), and I have not heard from her since other than she once visited the area where I lived with her husband via a mutual friend from Ireland who is in touch with them who had arranged it. I could hardly speak to her, but I was really happy and glad she was ok and that all turned out well for them.
But since then, other than one lovely lady who we are grreat online friends (Not the same one as above) but this lady has dissapeared and this lady is married so it is a no go there... (Even though her and her husband live separate lives)... But this lady also gets long term periods where she pushes everyone away... So I have not heard from her for ages. (A few years ago, I once met her when she had to travel down to the area where I lived as she was helping autistic children and families) She had a day off from that so I met her to show her the area, as I make a good tour guide...
Well, faceblindness struck again! Saw her approaching the car up off the beach, so I said "Good morning" etc, and opened the car door for her etc. She had a foreign accent (I had once spoken to her on the phone and she had a foreign accent) but somehow the acdent sounded from America which seemed the wrong country?
With that I saw this guy with adog walking up the beach looking concerned as this confused looking lady started getting into my car!
Puzzled, I saw another lady walking towards the car from the other side of the carpark towards me, and I suddenly realized I had got the wrong one! I apologized to this now relieved looking lady in my car that there had been a mix up, and the lady who I was meant to have in the car realized what had happened ans was laughing! (It was funny thinking of it!)
Then because the nurves hit as I drove, I had intended to impress her by driving down all the local little maze of lanes as I knew a shortcut, but I met cars going the other way so had to reverse back about half a mile, and with the nurves, when I went to go forward again as I had to work out which direction the other car wanted to go so I didnt reverse in th direction they wanted to go at the crossroads where they could pass, so when I went forwards and selected what I assumed to be the right way, I followed the narrow lane and ended up near in the villag with the beach car park we had started off at where she was much amused!
Not wanting to risk further embarissment, I drove the long way round to the first place I wanted to show her using the main roads instead of the shortcut!
The rest of the day was uneventful and I drove from place to place until it got dark (Was winter), and I eventually took her back, as she had quite a cold so could not feel the cold winter (It was freezing that day) so did not want to wear a warm coat... So I was concerned), so took her back to the warm place she was staying at, and drove home.
Anyway! What I am saying is regarding dating, is that many a lady I have not got her flirting hints and others only tell me later when I ask why was that lady acting weird!
But the ones who are forward and ask, I ended up so shocked that they would want to date me, that I said "No" when I really meant to say "Yes" because I was overwealmed and did not know how to handle the situation!
I hope this helps? (I am not saying it is the case with your friend, but for me it has happened).