I worked in law for many years and one thing I noticed is that there are a lot of people in that line of business who were more likely than not fairly dorky in their younger years.
Law school is a fairly promiscuous place, but the thing is that the students tend to be fairly bad at being promiscuous - it's a collection of dorks who never had that kind of freedom and ability before, so the playing field is leveled.
Older lawyers especially in large nyc firms tend to work at the office a lot. The years take their toll, and they begin to develop that paunch and lose their hair. There is a sense among many that life passed them by (and in most cases, they are right).
There is no shortage of women at law firms who sincerely find these men appealing because they admire their perceived intellect, perceived power, and perceived wealth. It's simply too easy to get over on fresh young female attorneys eager to climb the ladder at the firm, and a percentage are very willing to get down on all fours to do it.
Maybe some of the middle aged career military types feel the same way: life passed them by and their status makes them appealing to various women in their lives. As I have said before on FR, and a lot of people disagree with me, cheating and adultery have much more to do with circumstance and opportunity than they do with personal morality.
It's just the truth.
Had a 1-star as my brigade commander when I was in Germany who had a Spec5 as a secretary. The young lady was "one hot number", if you catch my drift. When He was transferred to the Pentagon, she went with him.
Yes, the guy was married. Yes, he was an older man.
Yes, everyone suspected the sectretary was doing more than taking notes.