Mo. Rev. Stat. § 566.023
It shall be an affirmative defense to prosecutions pursuant to sections 566.032, 566.034, 566.062, 566.064, 566.068, and 566.090 that the defendant was married to the victim at the time of the offense.
(L. 1994 S.B. 693, A.L. 1998 H.B. 1918)
*This section was amended by S.B. 491, 2014, effective 1-01-17. Due to the delayed effective date, both versions of this section are printed here.