Oral & anal sex, and sex outside marriage are still illegal in the military. UCMJ:
Art. 120. Rape and carnal knowledge
(a) Any person subject to this chapter who commits an act of sexual intercourse, by force and without consent, is guilty of rape and shall be punished by death or such other punishment as a court-martial may direct. (b) Any person subject to this chapter who, under circumstances not amounting to rape, commits an act of sexual intercourse with a person-
(1) who is not that person’s spouse; and (2) who has not attained the age of sixteen years;
is guilty of carnal knowledge and shall be punished as a court-martial may direct.
(c) Penetration, however slight, is sufficient to complete either of these offenses. (d)
(1) In a prosecution under subsection (b), it is an affirmative defense that-
(A) the person with whom the accused committed the act of sexual intercourse had at the time of the alleged offense attained the age of twelve years; and (B) the accused reasonably believed that that person had at the time of the alleged offense attained the age of sixteen years.
(2) The accused has the burden of proving a defense under paragraph (1) by a preponderance of the evidence.
Art. 125. Sodomy
(a) Any person subject to this chapter who engages in unnatural carnal copulation with another person of the same or opposite sex or with an animal is guilty of sodomy. Penetration, however slight, is sufficient to complete the offense. (b) Any person found guilty of sodomy shall be punished as a court-martial may direct.