There was a mod for The Elder Scrolls III: Morrowind which granted a talking sword named "Lilarcor" who has voice lines when drawn or sheathed, and complained about being idle for too long. It also changed and became more powerful as you got kills with it, so it wasn't very OP at the start of the game. Just a steel claymore. But it changed into better swords as you used it.

For this frostbrand, what if it had a muffled "mfmrmnrnmmm" complaining voice when it got bored in the sheath? Also, it obviously is a lecherous flirt, so it probably tries to neg or drop pickup lines to everything the party wants to kill if it is even vaguely female.