Consider that a citizen of Nation A physically travels to another nation, B, where they hire a prostitute in a transaction that is entirely legal in B, but would be illegal in Nation A only due to the monetary part of the transaction, i.e. the prostitute was not underage for either A or B. On their return to Nation A, if the authorities of A learned that their citizen had hired a prostitute in B, the citizen of A could be prosecuted.
Are there any jurisdictions in which such a law exist?
I am aware of laws where Nation A can prosecute their citizens for engaging prostitutes that would be underage in A while overseas, but this question assumes that the sex would be legal in A except for the fact that it took place as the result of an exchange of value, where such transactions in A are illegal.