Massage "misconduct" isn't directly defined as a crime... As is often the case, if a certain type of business has a licensing or overseeing body in the state government, that body imposes rules using administrative law, not criminal law.
MN Statute 146A.08, for instance, defines prohibited conduct to include, and I quote from statue:
"(d) Engaging in sexual contact with a complementary and alternative health care client, engaging in contact that may be reasonably interpreted by a client as sexual, engaging in any verbal behavior that is seductive or sexually demeaning to the client, or engaging in sexual exploitation of a client or former client."
But these are not crimes, they are license violations that expose the provider to an administrative fine of up to 10,000 and license forfeiture, but not prosecution.
BUT... HERE IS THE CATCH, and this is the biggie... Being a licensed, or unlicensed practitioner of massage or alternative health does NOT exclude you or your actions from MSA 609.321, which defines the criminal act of prostitution (a misdemeanor) as:
Subd. 9.Prostitution. "Prostitution" means hiring, offering to hire, or agreeing to hire another individual to engage in sexual penetration or sexual contact, or being hired, offering to be hired, or agreeing to be hired by another individual to engage in sexual penetration or sexual contact.
Subd. 10.Sexual contact. "Sexual contact" means any of the following acts, if the acts can reasonably be construed as being for the purpose of satisfying the actor's sexual impulses:
(i) the intentional touching by an individual of a prostitute's intimate parts; or
(ii) the intentional touching by a prostitute of another individual's intimate parts.
Subd. 11.Sexual penetration. "Sexual penetration" means any of the following acts, if for the purpose of satisfying sexual impulses: sexual intercourse, cunnilingus, fellatio, anal intercourse, or any intrusion however slight into the genital or anal openings of an individual's body by any part of another individual's body or any object used for the purpose of satisfying sexual impulses. Emission of semen is not necessary.