I think the most important thing is to teach them not to chase or grab him. At that age (boys especially, if they are anything like my nephew!) they might have a hard time accepting that Buddy may not want to be near them or accept pets.
I think it best would be have them sit down in his exercise area and hand-feed some veggies (long stems if he ever nips on accident). Teach them to just let him approach and explore them if he wants to. Even though the kids might want to hold him, it is very risky and honestly often kids have a bad experience because they get scratched. It is much more charming to have a little bun approach you willingly and sniff you all over. 🙂
Not sure how Buddy is with you, but if the boys are calm, you could try letting them pet his head and ears. One thing we tell have told kids is that the bum and tail area are the bunnies “go button”, meaning if you touch the bun’s bum it will go away! I think the level of petting will depend on how calm the kids are and how well they follow the instructions.
I wouldn’t let them hold him on their laps, and I would have everything supervised and on Buddy’s terms (meaning he can retreat to his area when he’s done interacting).
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The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.