Hi I think criston and Alicent were at it up to when Viserys was alive. When Aemond lost his eye everyone is like where was criston and theres this whole byplay between criston, Viserys and Alicent prior when Viserys calls her aemma and going to bed. Criston is right next to Alicent. Tbh I think they've been together a a long time romantically and it was consummated at some point. It's all hidden and veiled references on season 1 that probably become clear season 2. Alicent had a crush on criston and you see the look on her face when he tells her about Rhaenyra it's like extra betrayal. I think Alicent is living out her romantic fantasies with criston. Through a historical lens Alicent and Viserys marriage was the norm and often these women took comfort elsewhere. We know it's wrong but that's what happened then. Even age appropriate marriages like between Catherine the great and Peter were unsuccessful. She had affairs and illegitimate kids. So Alicent having an affair with criston is no big deal. I'm wondering though if I'm wrong and they finally consummate it when b and c happens and this is what causes Alicent's guilt. It's not sex based but just the fact she and criston were sneaking off. He was supposed to be on duty and he isnt. It just seems there is a history of them sneaking off together already.
On Whether Alicent and Criston Have Started Sleeping Together Before/During Driftmark:
I also read about the theory that Alicent and Criston had started sleeping together as early as Driftmark, which explains their absence during the fight scene between the children. What's worse, the thought had crossed my mind too the second time I rewatched the show. The whole exchange between Viserys, Alicent, Lord Commander Westerling, and Criston as Viserys goes to bed seems too purposeful to be ignored.
HOWEVER, it still seems implausible to me that they chose this night to sleep together in a different place where they were visitors and guests, staying over to provide consolation for Laena's funeral. What I am saying is that even if they might have already started sleeping together by the time Driftmark happens, it is unlikely that they did so on the night of Aemond's maiming. Even Rhaenyra went away, outside of the palace to seek Daemon so that she could evade the eyes and ears of potential onlookers. If Alicent and Criston had been secretive about their relationship which had become sexual by the time they were visiting Driftmark, I very much doubt that they would risk so much to spend one night together in a foreign place. And especially if they had become lovers at that point (which I hope is not true because it would be too early) it's not as if they could not wait any moment longer and they had to sleep together ASAP.
On the contrary, this is the exact tension we see at Driftmark from Rhaenyra who is constantly looking around for Daemon, watching him from afar, trying to get near him. So, yes, there is more sexual tension and yearning in the air between Rhaenyra and Daemon who have not been together in such a long time and can't bear to be apart for a second longer. And this is why they seek each other out at the beach, forgetting all about conventions, being guests of the Velaryons, and honoring Laena's memory. This kind of yearning I can understand, and it is given such build-up and progression in the episode that it makes sense why they would eventually sleep together.
Now, why would Criston and Alicent do so? In a foreign place? Not knowing who might be watching and listening from whichever corner? Endangering their trysts? Unless Alicent and Criston sneaked away to some remote location to just be by themselves it makes no sense why they would sleep together amidst the Velaryon household. And still, it makes no sense why they would sneak out anyway, since the danger of being seen is real. So, I do not think that on the night of Aemond's maiming Alicent and Criston are sleeping together.
Now, I don't know how the writers will approach the topic of their relationship and if they will reveal by what moment it started becoming physical, but again I find it improbable that Alicent and Criston had a sexual relationship while she was married to Viserys because it was just too risky for her and for him. Unlike Rhaenyra, Alicent and Criston would not evade Viserys' wrath and judgment by Westerosi standards if caught or if there was ever a slight suspicion that their relationship was anything more than that of a Queen of the Realm and her sworn protector.
