Tell them. A good manager will appreciate your honesty; if they can't afford to pay you more right now for whatever reason then at least it's an opportunity to

Tell them. A good manager will appreciate your honesty; if they can't afford to pay you more right now for whatever reason then at least it's an opportunity to discuss it and you can decide what to do from there. But if they can afford it and don't want to lose you, then you'll get a pay rise. #win.