You are getting so much dangerous info here.
If you hope to never get divorced, and are in a situation where she is already intermingled with the finances, there is nearly 100% chance she will eventually see on a credit report, or somehow see your email (if you go paperless with hidden account statements), or pick-up the discrepancy on the JOINT tax return, etc.
OR if you ultimately get divorced, it will come-out in the wash, and hurt you ten-fold.
If you love her to death, but you need the escorts to fulfill a unsatisfied void, find a way to earn a small cash income. IDK......help some kid with his paper-route and spit his pay.
The only suggestions that were semi-safe were the cash out at supermarket (if you throw away the receipt).....playing with restaurant tab when out with friends....paying a vendor for cash back, etc. Stay away from portion of paycheck being separated into different account.