dont store a knife with the point facing down, it damages the blade. no, dont do that either. when you store it with the point facing up you might accidentally hurt yourself when you try to grab it. dont store a knife at all actually. your blade must never leave your hand, always ready, ruthless and waiting. you know deep down that ever since you learned the stench of blood you will never be able to cast it aside. or just get a sheath for it i guess.

sometimes it's important to injure the character

sexualising a blade sliding between the gaps in plate armour

yes it's obviously penetrative imagery but it's also + more importantly about the intoxicating, terrifying helplessness of being violently reminded of the limitations of your attempts to defeat your own vulnerability