I get that we want the cuddle-bug to ourselves but monogamy isn't rewarded or encouraged in this game guys, we just have to take our wins when we get them; thank the Gods that the writers for Brienne and Aileh are around.
Well, actually, Brienne is also kind of polygamous, she doesn't want to fuck others, but she wants Champ to do it. Of course, with strictly defined people who are very dear to her, so it's more about "sharing happiness and joy with loved ones," but still. As for Aileh, she almost certainly has some fun time when she visits her mother, but it's nothing serious, more like a family tradition, having tea, eating a cupcake, having fun with a live sex toy, you know nothing serious.
Okay, fine, I'm just fucking with you.
And seriously, a pure romantic monogamous relationship sounds too good for these horny lands. Maybe at another time in another place for other people. Now go push that couple into a pool of corrupt honey!
