This is a very dark!Au in wich Gwaine is a mob lord and Arthur owns him a lot of money, so Gwaine manipulates(blackmail)'s Merlin into sleeping with him to drop Arthur's debt.
Fic:
Unpayable DebtsAuthor: anonymous
Warnings: DrunkSex; Non-Con due to blackmail
Summary: He was on his fourth drink when Gwaine caught hold of his hand and pulled him gently to his feet. His hand was hot and Merlin gulped, confused and dizzy. Gwaine just smiled at him and pulled him into another room. A room with a bed in it.
“You … you promise all the debt’ll go?” Merlin remembered to ask as Gwaine’s experienced fingers removed his clothes.
“All Arthur’s debt will fade,” Gwaine breathed back. “Now, let’s have a little fun, huh?”