It's not an official trait but there are parts of ASD that can cause it. For example: Having a person become your special interest, sensory seeking (for the more physical side of things), anxiety is a co-morbidity so that could play a part too.

I don't know. But I'm clingy and have ASD.

I cam say that Im not clingy and im diagnosed because ive learned that not alot of people are comfortable with excessive affection. They think of it uncomfortable. But i do understand some out there who do like this.

I'm ASD and I would say I'm a not overly clingy but feel that in the relationships I have had, I wished they were more clingy. I think it's because I have a hard time reading their emotions at times. I often ask "out of nowhere" if she is mad at me (thankfully she's not usually). I'm a late diagnosed individual (I was married before we knew), so I'm glad she loves me for who I am, and she has been supportive after diagnosis, which is also a blessing. So maybe I think being "clingy" as being obvious about how you feel in a relationship? Of course that's a blanket statement.

I'm clingy and have ASD. But I always have chalked if up to my Rejection-Sensitive Dysphoria that comes from my ADHD.