A little late of a response but this isn't entirely true. After Jez rats everyone out and they rescue Greyhide from the dungeons, Rowan can either accept the relationship or he can tell them to put a stop to it. If Rowan puts a stop to it everyone agrees at the time. But if her corruption is high enough, there is a scene while Alexia is working in the forge where she starts getting horny for Greyhide again and she can choose to say screw what Rowan says and fuck Greyhide anyways. Presumibly they wouldn't have told Rowan afterwards and would still be going at it occasionally off camera.