Idea: Conan The Barbarian/Cimmerian and Red Sonja, She Devil With A Sword reincarnate or get isekai'd into the bodies of Ned Stark and Catelyn Tully respectively, with the full knowledge and memories of the latter to properly know what's going on
On their wedding night, where Ned has to give Catelyn an heir, right before going off to war.
They instead go off and fight Robert's Rebellion together, whilst looking like the picture above
Robert can only ask when did Ned become more manly than him and why are neither of them wearing clothes and who came up with the chainmail bikini and why is Catelyn still alive and allowed to fight?