I spent yesterday evening painting the window frame in our toilet --
glossing over an undercoat I'd applied the day before.

This morning (10 hours later) the paint isn't even "touch dry" -- it's
almost wet. Any explanations or handy hints available, chaps?

The paint is Dulux (which I use because I've always been happiest with
that). Admittedly both undercoat and gloss are a couple of years old,
but they stirred up very well.

The only thing I can think of is that the room -- which is the smallest
in our house, ha ha -- has no window and there is almost no air
movement. I have put my dehumidifier in there this morning, as a kind of
forlorn hope.

Cheers
John