The "angle" is that the newspapers had a juicy story, but didn't publish it in order to exert influence over someone who could exert influence over them.
Its not in the public's interest to expose anyones private sex lives unless they are danger to society/life or demonstrate blatant hypocrisy .
The rest is titilation which is the tabloid shop window.
So why wasn't this story exposed for a titilation feast ?
I think generally the argument for caring about public figures' sex lives is that if they're cheating on their spouse, they're dishonest.
If they're single, what's the angle?
(awaits accusations of being a crypto-Tory)