Big Sister Attraction: One of the reasons why Yuri rejects Yor's marriage is that he's attracted to her.
Cigarette Burns: The interrogator before Yuri extinguishes his cigarette on Hayward's (the interrogated) hand. This is to lampshade how ruthless the SSS can be.
Dramatic Drop: Loid does this twice while doing the dishes, both times when Yor makes the excuse she didn't tell Yuri about her marriage because she forgot about it.
Faux Horrific: Yor is totally horrified when Loid comes in for a kiss in the final scene.
Hoist by His Own Petard: Yuri brought a bottle of wine hoping he'd be able to get Loid drunk and suss out anything suspicious. Not only did bringing the bottle cause Loid to discover Yuri is a Secret Police agent, Yuri ends up drinking a lot more than Loid.
Liquid Courage: Yor drinks straight from the bottle to gather the courage to kiss Loid.
Not His Blood: A flashback shows young Yor coming home to Yuri from an assassin mission with blood all over her. He is shocked but her inner monologue reveals that it wasn't her blood.
Right for the Wrong Reasons: Yuri is right that there's something suspicious about Loid, but it stems from his unhealthy attachment to Yor rather from actually discovering he's Twilight.
Saying Too Much: Loid quickly discovers Yuri is a Secret Police agent when the story he tells about the wine he brought does not fit with current matters.
Secret Police: Yuri works for the Ostanian State Security Service
