kissing could be considered sexual contact - and of course any of the "bases" for lack of a better description - and/or oral sex
here are the statutes as they pertain to those under aged minors
22-22-7. Sexual contact with child under sixteen--Felony or misdemeanor.
Any person, sixteen years of age or older, who knowingly engages in sexual contact with another person, other than that person's spouse if the other person is under the age of sixteen years is guilty of a Class 3 felony. If the actor is less than three years older than the other person, the actor is guilty of a Class 1 misdemeanor. If an adult has a previous conviction for a felony violation of this section, any subsequent felony conviction for a violation under this section, is a Class 2 felony. Notwithstanding § 23A-42-2, a charge brought pursuant to this section may be commenced at any time before the victim becomes age twenty-five or within seven years of the commission of the crime, whichever is longer.
22-22-7.2. Sexual contact with person incapable of consenting--Felony.
Any person, fifteen years of age or older, who knowingly engages in sexual contact with another person, other than his or her spouse if the other person is sixteen years of age or older and the other person is incapable, because of physical or mental incapacity, of consenting to sexual contact, is guilty of a Class 4 felony.
22-22-7.3 Sexual contact with child under sixteen years of age--Violation as misdemeanor.
Any person, younger than sixteen years of age, who knowingly engages in sexual contact with another person, other than his or her spouse, if such other person is younger than sixteen years of age, is guilty of a Class 1 misdemeanor.
22-22-7.4. Sexual contact without consent with person capable of consenting as misdemeanor.
No person fifteen years of age or older may knowingly engage in sexual contact with another person other than his or her spouse who, although capable of consenting, has not consented to such contact. A violation of this section is a Class 1 misdemeanor.
22-22-24.3. Sexual exploitation of a minor--Felonies--Assessment.
A person is guilty of sexual exploitation of a minor if the person causes or knowingly permits a minor to engage in an activity or the simulation of an activity that:
(1) Is harmful to minors;
(2) Involves nudity; or
(3) Is obscene.
Consent to performing these proscribed acts by a minor or a minor's parent, guardian, or custodian, or mistake as to the minor's age is not a defense to a charge of violating this section.
A violation of this section is a Class 6 felony. If a person is convicted of a second or subsequent violation of this section within fifteen years of the prior conviction, the violation a Class 5 felony.
The court shall order an assessment pursuant to § 22-22-1.3 of any person convicted of violating this section.
hope this helps you