Experience
About 12 years ago, I ended up meeting a guy through a singles group who was interested in the same education trajectory. We had even talked about dating even if there wasn't a spark. The night that we talked about it was at a party and I was excited. Little did I know that he connected with another friend of mine and took her as a date to one of the single's dances. While I was a little jealous of her, I was more mad at him because I had really looked forward to going on a date.
Note: She's on the spectrum herself
Flashing forward a few months later, some friends and I went to an art festival and he came with us. During that time, he flirted with me and talked about buying me a ring. So, I sent him a message but I never heard back.
A few weeks later, the friend, who he brought as a date was celebrating her birthday and he came with us. During the event, something about him being there was off. Additionally, my friend's sister said that she didn't like him because she felt that he was very condescending to another friend. Though be got a present for my friend, he brought it up that he had a girlfriend.
However, I found out much later that he led my friend on by trying to kiss her when they were alone. Additionally, it sounds like he would make plans with her and then bail at the last minute.