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...
I've warned you about this before, but don't
 develop unnecessary feelings for her.
حذّرتك بشأن هذا من قبل، لكن إيّاك
.أن تكنّ مشاعر غير ضروريّة تجاهها
Wie schon mal erwähnt,
gewinn die beiden nicht zu lieb.
Ya te advertí
de que no les tomaras cariño.
Ya te advertí
de que no les cogieras cariño.
Je me répète,
mais t’attache pas trop à ta famille.
Mi sembra di avertelo già detto,
vedi non affezionartici troppo.
Sei que já avisei antes, mas não crie
sentimentos desnecessários.
Я тебя уже предупреждал…
но ты с эмоциями осторожней.