喇叭口子 A Trumpet In The Throat
老魔接在手中，大聖在肚裡就聞得酒香，道：「不要與他吃。」好大聖，把頭一扭，變做個喇叭口子，張在他喉嚨之下。老魔接在手中，大圣在肚里就闻得酒香，道：「不要与他吃。」好大圣，把头一扭，变做个喇叭口子，张在他喉咙之下。
逐句解 Line by line
The old fiend took it in his hand, and down in the belly the Great Sage caught the smell of the wine and said, "He is not having that."
聞得 keeps the full dé — the twelfth and last verb-of-perception site in this chapter, and the sealed chapters have never once read one of them any other way. And the detail is precise: he cannot see the cup, so he smells it.
Good Great Sage — he gave his head a twist, turned it into a trumpet-mouth, and set it open at the bottom of the demon's throat.
喇叭 is a trumpet or horn, and 喇叭口 is the flared bell of one — anything funnel-shaped. He has turned his own head into a funnel and positioned it under the incoming liquid.
This is the chapter's last piece of engineering and it is the neatest. The bottle was defeated with a bow drill, the demon's stomach with a funnel — both of them ordinary objects, both used exactly as designed.
The smell is what sells the moment. Everything Wukong has done from inside this creature has been blind: he heard the third chief's warning, he heard the salt water ordered, and now he smells wine coming and knows he has about two seconds. The book never once tells us what he can see, because he cannot see anything.