No children cannot consent to sex so he was in the wrong and coercing any one into unwanted sex is rape full stop. The government has an interest in preventing rape and in protecting children. The government has no business telling adults that they can't fuck each other anyway they want to so long as all involved parties are consenting; whether money is exchanged or not.
Prostitution should be legalized and regulated--must be 18 or 21+, mandatory regular health checks, mandatory quarantine and treatment for any STDs, must keep records for disease tracking and taxes, mandatory mental health or social worker check ins on a regular basis to ensure the worker is voluntarily engaged and not being trafficked. Keeping it illegal and in the dark harms marginalized and at risk populations and allows trafficking to thrive
But given that it hasn't been legalized, mind your own damn business unless you think the person is being trafficked or you see them being harmed.