we aren't using it to pay bills, just doing it so I don't have to mention the money flow on tax.
Assuming US... Legally the IRS requires ALL income to be reported including from hobbies and illegal activities. Al Capone was imprisoned not for his mob activities but for tax evasion. (Voluntarily-reported illegal income cannot be used against you criminally because you are legally obligated to file a tax return and it is filed "under penalty of perjury" making the use of anything in it a 5th amendment violation of forcing you to testify against yourself.)
Worse, if you are a US citizen you have to report and pay taxes on your income
worldwide even if you have
never lived or worked in the US and are a citizen of another country. This can catch "accidental citizens" who were born in the US while the non-US parents were only visiting or where one parent was an expat US citizen. (You DO get a "foreign tax credit" so that you can 1:1 reduce your US tax by any income taxes paid overseas so at least it isn't double taxation.)