The only way this makes sense is that it's an honor killing.
Now this thread has officially entered the Twilight Zone.
The idea is simple. Mikey's two boys are coming of an age they will understand that their mother is not married to their father. This is shameful. Mikey has to marry her to expunge their sense of shame.
Unfortunately Mikey was married to Terri at the time, but Mikey couldn't just get a divorce from her since, after all, that, too was shameful!
A point of shame can be removed by eliminating the source of the shame. In the cultures that still use the "honor killing" that usually means killing the least powerful person in the conflict.
I note that Sicily was part of the Islamic world for several centuries. They may have been "Christianized" in a reconquest, but the "honor killing" tradition continues. It's really not surprising to see it resurface in Florida!
The Twilight Zone was Terri being allowed to be murdered without any of our leaders putting a stop to it and getting her back on the road to her recovery. Talk about the freaking Twilight Zone except for REAL.