Re: Santa Believers...
It would depend on the situation. Someone who doesn't believe because their family celebrates a different holiday instead is going to be different than someone making fun because the child still believes. The former is going to get an explaining that leans more towards different people celebrating different holidays and Santa knowing the difference. The latter is going to lean heavily towards bullies not knowing what they are talking about followed by a story or two about "Christmas magic." And the individual situation would dictate the exact answer, inline with how old the child is as well.