It’s perfectly legal to have an open marriage but (fortunately or unfortunately) the vast majority of US voters don’t see it that way. They didn’t see it that way in the ’80’s or ’90’s and they don’t see it that way today. That’s not what they signed up for when they voted that person into office. Thus, attempting to conduct an open marriage as an elected official (especially occupying the highest office in the land) is a most perilous endeavor. Bill Clinton not only had very bad judgment over the years but was/is likely a sex addict. And, unfortunately, there is no cure for that.