The reason why the son did it doesn't matter to the context of the post...
The H doesn't want to be a family anymore so Ignore his Text messages... he's a cowardly weasel
I just see this all the time...
The wayward spouse is WAYWARD and AWAL.. then a crisis happens (other than the infidelity) and the wayward spouse starts sending text messages like the give a damn...
My advice stands : Ignore his text messages and leave him squirm