The simplest solution is for Jon to become his wife for a few minutes and then end the marriage, whether by divorce, annulment, shooting Lucius in the head, turning him into a 10 year old, or anything else.
I can think of a lot of complicated solutions (such as swapping minds or bodies so that different people are married) but I can't for the life of me think of why any of the characters would prefer those to just being married for a few minutes. Even if they want to punish Lucius, they could just make Jon be married for a few minutes and then punish him after that.
