Intro: I’m watching Game of Thrones for the first time. I don’t know anything about it more recent than this episode.
King’s Landing: Tywin can simply order Tyrion to marry Sansa, and Cersei to marry Loras Tyrell, but for the latter he apparently needs to have a “friendly chat” with Loras and Margaery’s grandmother (who is played by Diana Rigg, btw!). This involves him accusing Loras of being gay, which Lady Tyrell parries by casually mentioning the “rumours” about Cersei and Jaime being Joffrey’s parents. Tywin ups the stakes by threatening to make Loras a member of the Kingsguard, which would strip him of the right to marry and carry on the Tyrell name, thus ensuring the end of House Tyrell. Apparently this is enough of a threat, and so Tywin extracts her permission for the marriage. Nobody messes with Tywin.
While this is happening, Sansa and Loras engage in a painfully farcical conversation in which she is trying to flatter and seduce him in her clumsy, naïve way, while he is clearly not at all interested in anything but escaping her company and seeking out some pretty man to be with instead. Sansa remains utterly clueless, the poor girl. If there’s one saving grace to the terrible things happening to Sansa, it’s that often she’s completely oblivious to them.