Spray or something to stop cracking paint getting worse?

[WolfOfBakerStreet]

I have a small section of ceiling in my bathroom that wasn't done with waterproof paint, and a small bit of cracked paint has developed.
To prevent it getting worse so I have to paint the whole area (I hate painting) is there a product I can get, like a simple spray, that would protect it and stop it getting worse?

 

[WolfOfBakerStreet]

ttt

 

[opps]

Without having seen the area, as a decorator, I would recommend sanding back any loose paint, applying filler as required and then applying two coats of water based eggshell (it might be prudent to seal the filler first).

 

[WolfOfBakerStreet]

Thanks very much

 

[JohnD]

Bathroom paint suffers from condensation.

Have you got a powerful extractor fan, and do you use it enough?