might as well be hung for a sheep as a lamb

might as well be hanged for a sheep as a lamb

One might as well commit a worse offense, since the punishment will remain the same. (In the past, theft of a sheep was punishable by death.) I've already blown most of my savings, so what's another $100? Might as well be hanged for a sheep as a lamb.
See also: hanged, lamb, might, sheep, well
Farlex Dictionary of Idioms.

might as well be hung for a sheep as (for) a lamb

Rur. might as well commit a large fault as a small one, since the same punishment will result. I'll take the expensive fishing rod. My wife will be mad at me no matter how much I spend, so I might as well be hung for a sheep as for a lamb.
See also: hung, lamb, might, sheep, well
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

(you, etc.) may/might as well be hanged/hung for a ˌsheep as (for) a ˈlamb

(saying) if you are going to be punished for doing something wrong, whether it is a big or small thing, you may as well do the big thing: I’m already late but I’ll stay and have another drink. May as well be hanged for a sheep as for a lamb.In the past, the punishment for stealing farm animals such as sheep was death by hanging.
See also: hanged, hung, lamb, may, might, sheep, well
Farlex Partner Idioms Dictionary
See also:
  • hanged for a sheep as a lamb, might as well be
  • I might as well be hanged for a sheep as a lamb
  • may/might as well be hanged/hung for a sheep as a lamb
  • might as well be hanged for a sheep as a lamb
  • hanged for a sheep (as well) as a lamb, (might) as well be
  • be blown away
  • be blown away by something
  • blown away
  • transgress
  • transgress against