If you're tired of hearing someone complain or whine, there are many synonyms that you can use instead of "more belly-aching." You could say they are "griping," "moaning," "whingeing," or "grumbling." Another word you could use is "carping," which means to make petty complaints or find fault. You can also describe someone as "lamenting," "bemoaning," "murmuring," or "grousing." If you want to use a more colloquial term, you could say they are "yapping," "whining," "fussing," or "pissing and moaning." Regardless of which one you choose, they all convey the same idea of someone complaining excessively.