I've hired masseurs who also provided escort services. Some of them have multiple tiers (e.g., therapeutic massage, erotic massage, escort session). This allows the provider to cast a wider net, as clients have different expectations and budgets.
An erotic massage might include the masseur being nude, MT, and an HE. The limits of the escort session depend on the client and escort, but would likely include sex. There is often a difference in massage quality, however, between trained masseurs who also escort and escorts who also give body rubs.
I think it's important to just be honest about your expectations and choose the appropriate service. For example, don't schedule a massage and try to fuck the masseur, unless you're willing to pay the escort rate. The masseur/escort should also be professional and avoid upselling during the session.