reverse pep talk
The inner monologue you recite to yourself to prevent you from doing something you know you shouldn't, however delicious and/or awesome it might be. To prevent remorse after said action.
Jane: I almost ate a whole tub of ice cream yesterday, but I gave myself a reverse pep talk and immediately felt guilty for even considering it.

Sally: I was going to text my ex last night after I drank some wine, but I gave myself a reverse pep talk and realized what a pathetic loser I was.