Just like any other case, affirmative defenses must be raised into the answer to a divorce action. This was illustrated in Lee v. Lee located here which the Mississippi Court of Appeals decided on Tuesday. The relevant language is below.
"¶15. Condonation or antenuptial knowledge, as affirmative defenses, must be specifically
pleaded or else the defenses are waived. Carambat v. Carambat, 72 So. 3d 505, 511 (¶27)
(Miss. 2011) (citing M.R.C.P. 8(c); Ashburn v. Ashburn, 970 So. 2d 204, 212 (¶23) (Miss.
Ct. App. 2007)). “Affirmative defenses that are neither pled nor tried by consent are deemed
waived.” Ashburn, 970 So. 2d at 212 (¶23) (quoting Goode v. Village of Woodgreen
Homeowners, 662 So. 2d 1064, 1077 (Miss. 1995)).
¶16. Chris did not raise condonation or antenuptial knowledge as an affirmative defense
in his pleadings. However, parties may try an affirmative defense through implied consent.
Mississippi Rules of Civil Procedure 15(b) provides:
When issues not raised by the pleadings are tried by expressed or implied consent of the parties, they shall be treated in all respects as if they had been raised in the pleadings such amendment of the pleadings as may be necessary to cause them to conform to the evidence and to raise these issues may be made upon the motion of any party at any time, even after judgment; but failure so to amend does not affect the result of the trial of these issues.
See also Lahmann v. Hallmon, 722 So. 2d 614, 691 (¶15) (Miss. 1998)."
The Appellate Court and the trial court found that the Appellant had waived the defenses by failure to timely raise them and they were not tried by consent. This is why I always plead this in answer to a divorce complaint just to be on the safe side.