I think the problem is that almost nobody is prosecuted under that statute, and indeed nobody would stand for widespread prosecutions under that statute. On the other hand, despite the Supreme Court's decision in Lawrence v. Texas, it would seem prosecution in this case might be justifiable:
The 435.03 statute is under employment in the state of Florida.
TITLE XXXI LABOR Ch.435-452
Chapter 435 EMPLOYMENT SCREENING
435.03 Level 1 screening standards.--
(3) Standards must also ensure that the person:
(a) For employees and employers licensed or registered pursuant to chapter 400, and for employees and employers of developmental services institutions as defined in s. 393.063, intermediate care facilities for the developmentally disabled as defined in s. 393.063, and mental health treatment facilities as defined in s. 394.455, meets the requirements of this chapter.
It is one of the reasons for not hiring someone to work for the state of Florida, not to prosecute Michael for cohabitation. I guess guardianships fall under the employment statute in the state of Florida.