There is actually a major bug in the Hogwarts dormitory rules.
Dormitory rule: Male students cannot enter the female dormitories, not even the corridors leading to them.
If the gender is the same, entry is still impossible unless the nameplate beside the dormitory door bears the occupant's name.
The problem lies right here: the names are hung outside the door. As long as someone takes the nameplate bearing their own name and hangs it on the door of the dormitory they wish to enter, they can pass through without any hindrance.
Over the past few days, this was how Wenxiu Lord and Severus managed to get Lucius's changes of clothes and toiletries.
Chapter 169