/diy/ - Do It Yourself

Over the past 5 years, the ceiling above our shower has progressively deteriorated.

Is this within reason, or should I be concerned? Reckon it's either normal use given the environment (wife has long hair and takes half hour showers at times), or a shitty vent is to blame ... or perhaps even a roof leak.

As it gets worse, my fears mount and I can't seem to ID it. The half bath on the other side of the wall also shows light color changes above the sink.