((Man this took a lot longer than it should have but here it is~
Okay so the story behind this is that when a rather irresponsible Magnus and Optimus were on Cybertron, Magnus drug Optimus to Maccadam’s Old Oil House. Optimus didn’t drink but Magnus got so overcharged, he threw Optimus across the room and Prime slammed into Nitra. Specifically, her breastplates.
This was some time before Magnus grew into the Autobot we know today~))