Just One Sip and No More! 

From James Clear, a master of pithy advice:

“It is not worth it to be greedy over a single transaction. Even if you’re not going to work with the person again. Even if you think word won’t get out. Even if you think this is your one shot to make it. Reputation follows you everywhere.”

I would add this: It’s not just that your reputation follows you everywhere, it’s that the habit of excusing yourself for behaving unethically does, too. If you think you are doing it just this one time and never again, you are fooling yourself.