One time I was working in a long term care facility and so many people would pull their clothes off if they didn't get their way. In the past they'd have gotten into trouble and sent to their rooms but with the Hissom project going on and so many law suits similar our admin decided to stop reprimanding people for their indiscretions.
As a result they'd yank their clothes off and run around screaming "Look at me!!! I'M NAKED!!!!!" and we'd pretty much ignore them. It took a while but they finally realized we weren't going to rush over and make them go to their rooms or give them what they wanted.
I was talking to a co-worker one day while we were hanging out downtown shopping and she said "You know what? If there were a dozen naked people walking around me right now I think I'm so used to seeing ugly butts and droopy boobies that I wouldn't even notice".
My point is that many people with developmental disabilities think taking their clothes off is a big deal.
In your case though he's an adult in public, not a facility, where strangers can see him and call the police, or worse, misunderstand this situation and shoot him for trying to show himself to their kids.
I'd like to suggest that it's perhaps time to find a facility in your area that takes people for daytime care and get him, and you, used to the idea of letting someone else help out. They usually have doors that require a key to open them. So even if someone takes their clothes off as part of their personality they can manage it behind locked doors to prevent him from serious repercussions.
He's going to end up in serious legal trouble and could even end up in a court ordered long term care facility. You know this, you also know that he's going to get you into trouble for not managing him. Please just consider having him go to an adult day care business so you can have a break and he can get some services through his disability.
I know this is hard. I know you love him and want to keep him at home as long as you can but he needs to have activities.
In my area we have a sheltered workshop where clients can have interactions during the day. They make friends, they have something to do. This might be something that your guy needs, to be out and with people who he can have interactions with.