I take a half dozen of my BPs to a couple of 5th-grade classes every year and do a mini genetics lesson. The kids aren't permitted to touch the snakes (which I am fine with in a class of 30+, for the snakes' safety), but they all get to see them up close and learn. Just pay attention to Max's body language. You will be able to tell if he is overly nervous, in which case you just make sure you have him out of everyone's reach. Explain to the kids that they need to be calm and move slowly, or he might be afraid that they will hurt him. This helps them understand that snakes can be scared, too, and gives them a gentler edge. Only allow one hand at a time if you allow petting, and never his head, to minimize his stress. He (you) will do just fine.
Oh, and if you do allow touching, take Max to the kids while they are sitting calmly. This will help lower the energy level in the room, rather than kids jumping up all excited to run up and stick a hand out. It will also lessen the change that Max will interpret that hand as an aggressor.