How did the other apostles besides Peter carry it off, before they received the gift of the Holy Ghost?
How about David in the OT, before Bathsheba?
Even unreligious men won't commit sin, while others are watching.
Under the threat of retaliation, men will act contrary to their nature.
Under the threat of imprisonment, men will act contrary to their nature.
Peer group pressure will create a sin free environment.
Do you know any Mormons?
They are sometimes entirely different around their group, than they are in the world by themselves.
There is a joke in these parts about...
How do you keep a Mormon from drinking all your beer on a camping trip?
Bring another Mormon.