You need to confront with maturity and confidence. Take him aside and explain that the he is over looking certain issues with your pay but then offer to remind him regularly about this so he feels less at fault.
Say... Sorry I should of reminded you earlier but you overlooked this (show him slip) it's partly my fault because you're a bust man but I'd appreciate it if you could take ten minutes to talk with me so we can get this sorted out.
Say... Sorry I should of reminded you earlier but you overlooked this (show him slip) it's partly my fault because you're a bust man but I'd appreciate it if you could take ten minutes to talk with me so we can get this sorted out.