What is the moral calculus of atheists

There are a number of professed atheists in this forum. I was curious as to what sort of moral imperative atheists are beholden to when presumably no one is looking.  Speaking as a theist, I am constantly cognizant that there is a God who considers what I do and is aware of what I do, even though that awareness on my part may not always result in the moral behavior which I aspire to.  But let’s take a fairly mundane example — say theft.  We’re talking about blatant theft in a context where one could plausibly or even likely get away with it.  I affirm to you that as a Christian, or more relevantly possibly, as a theist, I would never do that.  Possibly it has just as much to do with my consideration for the feelings and rights of  some other individual, who has “legal” possession of said items, as it has to do with my awareness of an omniscient creator who is aware of what I’m doing and who would presumably not bless me if I violated his laws.  I mean,  I care about the rights of other people.  And, considering other moral tableaus, those of a sexual nature for example — I would personally never consider going to a prostitute for example, in that I feel empathy for that person, and how they are degrading themselves in the sight of God, and how I would not want to contribute to their degradation, so that my own human lust would never result in me victimizing another human being in that way.  So in summary,  there are all sorts of constraints on my personal behavior that stem directly from my belief in God,  and I am honestly curious about the inner life of professed atheists in such matters.  In other words, do atheists for example, in such junctures of moral decision, only consider whether they can get away with it, i.e escape the detection of human authorities?  I am just honestly curious about the inner life of atheists in such matters.