if you explain to your custys that YOUR there window cleaner and this guy is working on the side then you should have no problems.
dont report him as if you ve had him working with you no doubt you ve probably broke the law as well.
dont ever take on anyone again and either look for better paying work and go wfp if you havent done so already
preferably both then you will earn more money without the hassle of employing
regards
dazmond