The best answer here, which is honest, straightforward, and has the least chance of being inflamatory is something like "Sorry, I don't have time to help you wi

The best answer here, which is honest, straightforward, and has the least chance of being inflamatory is something like "Sorry, I don't have time to help you with any of your ideas, I'm already working a bunch of my own ideas" (although, I might stick the word "shitty" before both instances of "ideas", depending on the audience, to communicate my position on Sturgeon's Law).