Prefacing this by saying that DH is lovely in so many ways, we have a great relationship apart from twice a day when I could quite cheerfully throttle him.
Currently pacing the house in my PJs because I can’t get in the bloody bathroom to get ready for work as he’s been in there for the last 40 minutes. The shower isn’t even running yet so that’s 40 minutes sat on the toilet pissing about on his phone. This is a daily occurrence - using the bathroom, having a shower and getting dressed takes him at least an hour, usually closer to an hour and a half. Meanwhile I’m running round getting the DC fed and dressed and trying to tidy the house before I get chance to dive in there for ten minutes and do what I can to myself in the time I have. Luckily I work from home so don’t have to be too presentable, but I’d still like to have time for a proper wash in peace! It’s not just work days either, I’ve lost count of the number of times I’ve gone on days out with wet hair and no make up because I haven’t had time to get ready properly.
Then after work he’s back in there for another 40 minutes having another bathroom break, while I’m feeding the kids and getting them sorted for bed. Every day 
I’ve tried reminding him that we have one bathroom between four people, hammering on the door and telling him he needs to get a bloody move on, suggesting he sees a doctor for what is clearly chronic constipation and even once hid his phone which did result in a much shorter trip 
Speaking to other people it seems that this isn’t even that uncommon. What in the name of fuck do men do in there for so long? And short of rigging the shower with some kind of remote controlled shock mechanism, how do I make him pack it in?