Imagine a time when a colleague contributes a shitty spaghetti of non-optimized code that neither use mnemonic variables nor conventional naming of functions, and you can imagine the dark hours of maintaining it and your fingers itch to fix it but you don't have the time and the responsibility too to do it. He doesn't listen to you and you feel bad to tell this to the boss as the colleague is also a friend you've known since college and is a good person otherwise. No options seems to give peace.