Pain peeling problem downstairs bathroom

[BathDIY]

Got a paint-peeling problem in the downstairs bathroom, paint cracked a little while after going on and this has got much worse since I started having to store wet towel in the room (unavoidable at present).

Background is:

• This area used to be tiled
• I mist coated the walls before painting
• The window does not have a vent (I lock it open a little to provide ventilation at moment)
• I don't think there is enough space to add in a fan

What options do I have other than locking open the window?

 

[sparkwright]

Any PVA been used? (hopefully not)

Any grease or paste or similar found it's way on the surface?

If you think that is moisture related, and it probably is, then the big question is
'Do you have an electric extractor fan?'

If not, I seriously suggest you get one.