Of course monogamy is real.
That is basically like asking if rain is real. It exists whether you choose to believe it or not and you will change your mind when you feel it pouring down and you get wet. My sister, cousins and most of my friends have been happily married and in relationships with their husbands and Wives for around 15-20 years and my Wife’s Auntie and Uncle celebrated their 40th wedding anniversary last year and the two of them have been friends since they were 8 and have never been with other people. My Nanna and Pop were the same and after she passed away twenty four years ago my Pop never remarried or dated another woman because my Nanna was only woman he loved. I got engaged to my best friend (Jackie) when we were young and I only wanted to spend the rest of my life with her because I loved her but she passed away when she was 17 and I tried committing suicide a few times to be with her because I didn’t see the point of living without her but my sister stopped me.
I think your question should be ‘Do you think people capable of being faithful to one person?’ and to answer that question I would definitely say yes and I would never cheat on my Wife because she and our daughters mean everything to me and I love her more with every year.

I kiss, cuddle and touch some of my female friends when I see them and say goodbye to them and it is just a way of being friendly to them and my Wife is perfectly okay with that and when you see the people you mentioned are you sure you aren’t confusing that for more?