I'd say those are both shady behaviors belying ulterior motives.

Manipulation

I'd say that second one is nearing a sunk cost fallacy making it akin to cognitive dissonance. That's the term usually described in addiction and certain splurge purchases, meaning that your brain will try to reason around anything against a certain idea.

Example: I shouldn't have another drink because I still need to drive and I have got a pretty busy day tomorrow. Then again, I could always take the bus home and call in sick tomorrow. I deserve another drink because I worked hard today.

Justifying. Basically you already have a behaviour in mind, but you need an excuse to execute on that behaviour.

It can also be retroactive. You can create an excuse for your behaviour after you've already done something -- retroactive justification.