Play it cool

Firstly, I would suggest not sharing your exact age here, especially if you're underage. I don't think you have much to worry about if the situation is as you've described. It's not like he's trying to do anything sexual with you or copping a feel or anything like that. To any outside observer it looks like a special needs kid who's made a connection with someone and parents of a child with his kind of limitation would probably be very appreciative of that. And if he normally avoids touch the parents may be even more appreciative to see him break that pattern with someone. Parents of autistic kids just want their kid to have a normal fulfilling life and physical contact is an important aspect of that whereas most other people would just take physical touch for granted to the point of suspicion. For a kid like this it's a ray of hope for the parents. If you're female, then they'll certainly won't be perturbed by it; and even if you're male, you might get a free pass once in a while. Just don't act like you're guilty of anything because you're not. It's probably a good idea to avoid any situation with the parents walking in on you unexpectedly with him on your lap after they've been away. You don't want them to get any ideas about what might be going on while they've left you alone with him. But if anything like that happens when the parents are already there, just roll with it and don't get anxious about it. You're going to want to react the way they would react as parents, pleasantly surprised to see him get out of his bubble and happy for him for making this kind of breakthrough. Of course, you shouldn't be too excited, just positive about it. Try to mirror the parents' level of emotion. It will help reassure the parents that you're on the same page as they are. I'm not sure you need to worry about leading him on. It all depends on the boy's expectations. If "leading him on" means he expects to keep seeing you for babysitting, that doesn't seem like a problem. It's only a problem if he expects something you can't provide and if he has a crush on you, it's not like he's going to expect anything beyond the status quo. Even with a non-autistic kid, a little innocent affection goes a long way. There's not much of a chance that you'll lead him into expecting you to engage in anything more questionable than that. But there is a chance that he'll come to rely on you and might get upset if the parents switch up what babysitter he gets. I'm guessing he's had other babysitters before, but if he bonds with you, then he may become more insistent. You need to decide if you're able to follow through on that (within reason). The parents will be happy if you're flexible, but don't bend over backwards. Even with parents you need to play a little hard-to-get so that they don't worry about you being too eager for the role. And you probably know well enough to ignore anything Tyred says especially after openly advising you to out yourself. She is not to be trusted in any capacity at all as she is well-known as an anti (anti-pedophile).