I think you have the right approach, but infidelity is not "strongly immoral" in the sense that it entitles you to publicly humiliate people you aren't in any way related to. It's a private matter between two (or actually, more) people. Your spouse has the right to tell you what you did is "strongly immoral", but Joe Public doesn't. I have zero respect for someone from the public who thinks their moral outrage entitles them to shame someone else for who they have sex with.

"Strongly immoral" which belongs in the public sphere is more like human trafficking, murder, corruption in public office, etc.