I'm sorry this is insane. Why is it moral to divorce your partner unilaterally (which by necessity is behind your partners back) while cheating is somehow worse. This is retarded pearly clutching to think one is good and the other wrong. Bunch of hypocrits, the lot of you.

You can reconcile during or after a divorce. You can discuss it and reduce the harms it might cause. Cheating is an impulsive decision that can destroy any trust one has in their partner and introduce things that can't be mitigated, like STIs.

To be clear, it's better to not do either, but given the options, one is certainly better than the other.