Exactly.
If this was a commoner's marriage would anyone be at all surprised if it ended in divorce?
Man- getting on a bit, convention required a virgin for him as a bride, (pretty rare find in the 1980s) domineering father said come on, get a move on, here's a nice girl for you who is suitable and we need a children for the family 'line'.
Woman- still a teenager, no real life experience, 13 years younger, never had a proper relationship, or much of a job, not educated, starry eyed at the prospect of an older man with status.
They had a few dates, barely knew each other, didn't have much in common (reported as Radio 3 lover marrying Radio 1) but hey, the dress was ordered, church booked, tea towels printed.
Add to this he still had a soft spot for a woman he's dated years before who didn't fit the virgin requirement and was married anyway.
Terrible match, predictable outcome, both had affairs before a messy and public divorce.