In my 30’s when I was married to my first wife she slept with several other men and ladies. Sometimes they would stay over and have sex with her in our bed, other times she would stay with them and come home the next day.
She liked telling me what they did together and I would enjoy hearing about it while fucking her. If someone had stayed the night with us I would get up first and take our 2 children to the beach or a park and then somewhere to have breakfast.
This would give my wife more time with her partner and I would call from a public phone with 3 or 4 rings to warn that we were returning home. I have never felt that I was a “cuckold” in the negative sense and have always thought that women should be allowed to enjoy a happy sex life with partners of her choosing, married or single.
I must add that my wife had a high sex drive and never declined my advance and initiated much of our love making herself. We parted good friends as we developed different interests and our children grew up and moved on, I have never regretted those times.