That's a very narrow view that's a function of one's religion, culture, and values.
When I was in school, (US) my very Catholic French teacher explained that his uncle, in France, had a mistress. His uncle's wife knew and was okay with it. What my teacher was explaining is that the culture around marriage varies considerably through the world, and you can't take for granted that what we were taught (monogamy) is the standard that others live to, or even expect from you.
He is an immigrant, he holds dual citizenship in Taiwan, and regularly travels there.
I didn't go so far as to find out if he married in the US or elsewhere, or if his wedding was Christian.
What I do now is that in some cultures in that part of the world, it is acceptable for a man to visit a prostitute during a business trip. It's not something I condone.
I should also point out that in the US, there's no standard wedding vows! I don't think you know what vows Huang made with his wife; nor do I think you know what their expectations were in their relationship.
Please don't make the mistake of assuming that American culture is homogeneous: It's not.
That’s not quite true. A more accurate statement would be: A marriage may be annulled in some U.S. states if one spouse entered the marriage with a concealed, permanent intention not to consummate it, and that intention constitutes fraud going to the essence of the marriage.
If the couple was having sex after marriage, and then one partner decided to cease having it some time later, that is generally not grounds for annulment.
If it were permitted, this would make many, if not most, late-stage marriages subject to annulment. People get sick and injured or just incapable in old age.