Decorating mess-up - advice appreciated!

Hi,

Some idiot (me) painted a coat of matt emulsion on to bare plaster coving without priming it first (I know - I misunderstood something )

My question is - what should I do next? I am obviously worried about it starting to crack and flake at some point, although after doing some online research some people say they have got away with it. But I'm completely undecided as to whether to try to now seal the coat I've put on with something to try to avoid it flaking, or whether to just leave it and wait to see if it starts to crack, then remove the flaking paint, prime then re-paint. Any advice would be much appreciated

Is it decorative cove or the gypsum type with a paper face?

I'd wait to see if it cracks, if it does then decide what to do.

Might need to sand it down, try and prime it and go from there.