A lot of affairs are conducted by arsewipes who don't give a shit about their commitment or the partners. No respect. Totally agree with that.
BUT
My DH came out of a decades long abusive, alcoholic, drug induced, violent narcissistic "relationship". His self worth was less than nothing. He would never have had the courage to leave, that ingrained belief that was systemically conditioned into him that he was not worthy, without the insight of a person that actually valued him and could see him for the person he is. He STILL has problems believing that.
Do you think he could have left someone so abusive, who would verbally and physically attack him, with knives at times, gaslight, emotionally blackmail, and make him feel like a worthless "shit cunt" without a light at the end of the tunnel?
All of his immediate family and friends, who knew some of what was going on, and that's some, they don't even know all of it, breathed a sigh of relief and a thank god he's met someone else. They didn't care a jot about her? Why was that? Because they thought he was scum and judged him?
Don't tar everyone with the same brush because unless you've been in that situation you don't know what the fuck you're judging.
It's years on and he's in counselling. He's a very damaged person because of what the abuser did. Oh, of course she's now the victim because he had the audacity to leave (although she cheated in the relationship but of course, history is rewritten)
Do I feel bad he was married at the time.
No.