Sin is not always the product of venial inception. A classic example is that of curiosity. How many has Shaytaan lured with this benign snare into the lion's den? What began in innocence ends desecrated. That's what you call mauradery.
The greater the treasure, the more assiduously one stands sentry over it. The same applies with the Qurb of Allah (SWT). The more one has, the more he or she will avoid anything that could potentially place it in jeopardy.