A mystery

The small bay tucked into the coastline  on the far right is a stony  cove beneath towering cliffs that crumble and slip from time to time.  Rubbish gets washed up on the beach. It's not normally a place that people visit, let alone linger. There's no easy access. Walkers walk on by. 
In the past I've occasionally found things here like old fish crates and once a dead seal so I usually go down for a look.
Today the tide was half in and I could only get as far as the big wedge of rock you can see sticking up from the tideline  in the first extra pic.
Just beyond it there's  a cleft in the rockface, hidden from view unless you go close up to it. Which I did - and I saw something that surprised me - see extra number two.

LOVER AWAITS IN LONDON

What's the story here? 
The lettering, neat and clear and high up (beyond my reach but I'm only 5'3") isn't that new. The paint is lightly coated with green algae - it's been here a while.
Was this a rendezvous for two individuals who sought out a private (but stony!) trysting place? Did one of them get suddenly called away, or back, to London, leaving this secret message? Did they ever re-unite? 

Or could the story be quite different. Several small bays along this coastline have been drop-off points for drug consignments. Could the words have been a coded message, a warning perhaps that the coast was not clear and the drug squad were on to them?
Who knows? 
What do you think?