Honestly, I don't like doing the Santa Lie with kids, if only because you're playing Russian Roulette with their feelings. Some small percentage of children are really hurt and feel betrayed when they find out, often with lasting effects.

However, since I live in a society that does that, I know the rule: you don't ask kids if they believe or not, because you're putting silly ideas in their gosh darned heads! And seven is still an average age to believe in impossible things like Santa, which any parent ought to know.

Man's an ass and a bad parent.