Fat chance of me ever paying for sex with a Credit Card or Bank Transfer. Cash, in person, only, ever.
As well as give them my real, full name from my CC/Bank, why not just give them my address and social media profiles as well. Hell, give them my logins and PIN numbers while I'm at it.
We all know Sergei is completely trustworthy and your friend, it's not as if he could be involved or have connections to any form of organised crime here or abroad.