The same could be said about any dog, cat, guinea pig or hamster. How many kids are bitten by their friends pets? Tons. Legally you are responsible for any DAMAGE done by your pets, regardless of what that pet is. We're still talking about baby ball python here not a 12 foot Egyptian cobra right? What could it do? Still a good idea to talk to the parents first before having their kids come into your house for any reason. Stange adults inviting their kids kids into their houses can make parents uncomfortable animals or not.
I feel a little light headed... maybe you should drive...