It looks like divorce is an upcoming feature:
(UPCOMING) Autonomy, Autonomy, Autonomous Drama!
This will be the optional part of the mod that enables other parts to happen autonomously, for players who want more drama! Want your Sim to autonomously ask to put a child for adoption, adopt, or stop using protection? Want Sims to be more often able to ask for breaks in relationships, or full on break-ups or divorce, amicable or not? Want your Sim’s NPC wife to confess to an affair out of the blue? This will be the add-on for you.
