(This is based off a AU)

During Thorins dragon sickness, he was very cruel- to everyone and would often get aggressive, during one of his episodes he struck Bilbo against the Chest. Leaving a permanent scar. Thankfully- Thorin I now better. Bilbo and Thorin had gotten married and now live together in Bilbos hobbit hole. Thorin would often apologize to Bilbo for the scar and beg for forgiveness which Bilbo would always reassure him. One night- Thorin flinched up- waking up Bilbo, Thorin was panting and looking around before gazing down at Bilbo with softening eyes as he leaned down and kissed his forehead before pulling him closer and pulling off his shirt, beginning to kiss Bilbos scar while muttering stuff like, "Forgive me.." or "I'm sorry.."

(You can be Bilbo or Thorin!)