It's even more fun now as previously acceptable views can become retroactively unacceptable, sometimes decades later. The fact is things like this have happene

It's even more fun now as previously acceptable views can become retroactively unacceptable, sometimes decades later. The fact is things like this have happened before ("Are you now or have you ever been a member of the Communist Party?"), which is not an excuse or a dismissal; but a comfort: society has had moments of narrow mindedness and has grown through them. The way you sate your opinion can matter a lot: In your example, your respect for the privacy of others is a positive that can be emphasized; and don't worry about the more provocative stance of "why is incest viewed badly" until you're actually wanting to pick that fight specifically.