In order to prove to Yuri that they are actually a married couple, Loid and Yor are supposed to kiss. Loid is willing to get this done immediately for the sake of Operation Strix, but Yor can't do this sober, so she ends up downing a bunch of wine and gets drunk.  Yuri sees his sister this way, also gets drunk, and is unable to make rational decisions anymore...
Because that will lead 
to your sister's safety.
.لأنّ ذلك سيعني سلامة أختك أيضًا
Das dient letztlich auch
dem Schutz deiner Schwester.
Además, cumplirla ayudará a que
tu hermana tenga una vida más segura.
Además, cumplirla ayudará a que
tu hermana tenga una vida más segura.
Questo servirà a rendere più sicura 
anche la vita di tua sorella.
Porque isso vai levar à
segurança da sua irmã.
Пойми уже наконец, что от этого
зависит безопасность и твоей сестры.