"Get dressed with the lights on, there's nothing worse than accidentally putting on someone else's pants and socks"
Then Steve pointed out:
"Hmm. Don't know - there's nothing worse than waking up to see some other bloke putting his skivvies on..... "
So, here's the plan from me:
"There's an en suite bathroom... I suggest we take it in turns to enter it/leave it fully clothed (doing any necessary changes behind its doors)"
I don't speak sense often, but in this case, I've made an exception.