A typo that spawned a brand new and awesome word. Something is considered sinfuriating when you want to do something sinful, but circumstances don't allow you to accomplish the act. Not being able to do the sinful deed then infuriates you, causing sinfuriation.
God I wish we could have sex right now! It's so sinfuriating that I don't have a car!
Not being able to rob the bank because you left the fucking guns at home is so sinfuriating!
I want to kill my grandmother for her inheritance. It is so SINFURIATING that she locked herself in her room!