masking tape pulls paint off

[Triangle123]

Hello

Sorry if this seems really simple but I just wanted to get some advice: I tried painting our bathroom (accidentally with normal wall & ceiling paint) last year. Every time I took the masking tape off, the paint came off with it (despite using different tapes, hairdryers etc). Firstly, is this because of the paint I added (the newest layer) or paint the previous owners added (the layer underneath)?

Do I need to sand down the old paint before putting bathroom paint on top? If so, how far do I need to sand down? Do I need to use an undercoat before putting bathroom paint on? Does anyone have any general tips to support repainting the bathroom and/or removing paint, please?

Thank you

 

[footprints]

Chances are it is the layer beneath you are not getting a good key on it, might be very shiny greasy from soap etc, or some idiot has used some kind of polish on it (unusual in a bathroom) as we do not know the cause the safest way is to clean with sugar soap and apply a good primer like Zinsser Bullseye 123 always use low tack tape on paint (Frog is very good) try to let the paint harden for at least a couple of days before taping, fact is that most paints while they dry in an hour or so take weeks to fully cure. Peel tape by keeping your hand close to the wall so it peels back over the fixed bit not pulling straight off the wall.
Why are you needing tape? Is it to do stripes or just to mask for silicone?