sealer in ceiling paint?

I am getting to the painting stage in my little house and have a question about painting ceilings.
I like to mix 5 in 1 sealer into the wall paint so that it's easily washable (woofies in residence) and it also gives the paint a slight sheen. Can I do this to paint the ceiling as well?
My concern is trapping moisture between the roof sealer and the lightly sealed paint which may (or may not) cause peeling. As it is now, my roof is well sealed but the ceiling is just ordinary flat paint that can breathe.
Comments good, bad or ugly always appreciated. T.I.A.