(a) A person commits an offense if the person knowingly engages in any of the following acts in a public place or, if not in a public place, the person is reckless about whether another is present who will be offended or alarmed by the person's:
(1) act of sexual intercourse;
(2) act of deviate sexual intercourse; or
(3) act of sexual contact.
(b) An offense under this section is a Class A misdemeanor, except that the offense is a felony of the third degree if the actor is civilly committed as a sexually violent predator under Chapter 841, Health and Safety Code.