The Shepherd and the Wolf

No Moral. Suggest us a moral of this fable in comment section.
A Shepherd once found the whelp of a Wolf and brought it up, and after a while taught it to steal lambs from the neighbouring flocks. The Wolf, having shown himself an apt pupil, said to the Shepherd, “Since you have taught me to steal, you must keep a sharp lookout, or you will lose some of your own flock.”