There are times when a parent is intentionally unemployed/under-employed and living off income of new spouse where the court will look to a new spouse's income in calculating support. However, if the other parent is gainfully employed, the only impact new spouse income will have on child support is a the potential of reducing support based on the paying spouse being in a higher tax bracket as described by Mr. Azemika.
There are private investigators that can assist in tracking individuals who are working "under the table" if you are having difficulty proving undisclosed income. Beyond looking to the standard of living/claimed living expenses on the parent's Income and Expense Declaration compared to his pay, sometimes it is appropriate to issue discovery such as demand for production of documents (like bank records and loan documents), and/or subpoena bank records to show deposits/extra pay/claimed income on loan applications to prove higher than disclosed income. You can argue for imputation of income to a party who has the ability and opportunity to work based on factors such as training, education, experience, age, health, special skills, licenses, etc. and proving jobs for which the other person is qualified are available in the general area. Hope this helps.
How about get yourself a job and stop trying to squeeze money out of your ex. Child support is supposed to help support the child, not fully support the child. Women these days need to get off their butts and get jobs and stop living off their children's fathers.