What do atheists say when someone sneezes?

[Fromper]

My wife always says, "God bless you" to me, so I always feel obligated to say it when she sneezes. The thing is she has severe allergies and often goes into sneezing fits. I learned very early on to wait for that last sneeze before I say anything. One time she had a fit in public, and this lady kept saying, "bless you" with every one and gave me weird glances like I was an asshole for not saying it.

I hate stupid cultural obligations.

I usually say something on the first one or two, then joke about how they're over their quota if they hit more than three. It's polite, without getting redundant.