So yes, you won't get deported when arrested for prostitution, but your entry to the US will be denied for a couple of years after the arrest. Also, prostitution (like drugs) is considered a "crime of moral turpitude" (which basically means you have no morals), So if you ever marry a US citizen, or apply for a greencard or any type of US student, work, business visa etc.. you won't be eligible because of that bloody prostitution arrest 5 years ago...